SIRS BRANCH #1 GARDENING GROUP
April in your Garden
Revised 3/26/08
Table of Contents
Page #
1
2 1 Plant:
2 A. Summer color, both annuals & perennials
2 B. Cool season plant you can still plant
2 C. Summer favorites
2 D. Bulbs, corms and tubers
2 E. Groundcovers
2 F. Vegetables
2 G. Tomatoes
3 H. Herbs
3 2 Citrus and other tender perrenials
3 3. Lawns and ground covers care
3 4 Soil preparation and fertilization
4 5 Subsequent fertilization
4 6 Fertilization general
4 A. Azaleas, Camellias, Rhododendrons and Hydrangeas
4 B. Roses
4 C. Lawns
4 D. Cymbidium orchids and others
4 E. Citrus
4 F. Hydrangeas
4 G. Citrus and other fruit trees
4 H. Azaleas, Camellias and Rhododendrons
4 I. Plants in general
4 7 Special maintenance care
5 8 Grooming: A. Deadheading, B. Groom and feed spring bulbs
5 9 Compost
5 10 Maintenance: Dig or hoe weeds
5 11 Prune: A. Frost damage, B. Flowering trees-peach, plum, etc; C. camellias, D. fuchsias,
E. geraniums, Japanese snowball, geranium, hydrangeas, clematis, wisteria, F. roses.
6 12 Propagation: Seeds and cuttings
6 13 Slugs and snails
6 14 Sucking insects:
6 A. Aphids -Bayer’s 2 in 1 systemic Rose & Flower Care, ants
6 B. Scales - Bayer’s 2 in 1 systemic Rose & Flower Care
6 C. Spittle bugs
6 D. Yellow jackets
6 E. Oak moths
6 15 Codling moths: moth traps and control
7 16 Drip irrigation with timers-reasons
7 17 Drip irrigation: plasticulture and fertigation
7 18 Drip irrigation maintenance and adjustments
SIRS BRANCH #1 GARDENING GROUP
APRIL IN YOUR GARDEN
Revised 3/27/2008
For maximum use of this guide, use a highlighter pen and highlight those plants you wish to buy and plant, and other chores you need to do.
Plant: April is a busy month for planting in your garden. (See soil preparations 2. below before you start planting). A. Plant for summer color-both annuals and perennials, remember the small pony packs (6 cells) will normally produce the best plants. Also, the best plants are the smaller ones, which have only a few blooms. Plants in the larger 6 packs are usually in full bloom, with roots coming out of the drain holes, and each of the 6 cells will usually be root-bound. Most pony packs are black plastic and slightly smaller than the larger 6 packs. However you may find that many of your selections may not be available in pony packs; nurseries like OSH appear to have discontinued stocking many selections. Seasonal big movers like petunias, impatiens, marigolds and pansies are the ones most likely to be available. However if you are willing to buy 6-10 (pony packs) of the same plants, some of the smaller local nurseries will order them for you. However, one of our local suppliers of pony packs has closed down his nursery, which leaves one less supplier of these. B. It is still not too late to plant cool-season plants such as Dianthus, pansy (Viola wittrockiana), primrose (Primula spp,) or other Viola spp. C. Also summer favorites such as Ageratum, Cosmos spp., globe amaranth (Gomphrena spp,), impatiens (usually Impatiens wallerana), Lobelia (usually L. erinus?), marigold,(Tagetes spp.) Petunia (P. hybrida), Salvia (many highly variable species), statice (Limoniun sp. usually L. perezii), sunflower (Helianthus spp.), sweet alyssum (Lobularia maritima), Verbena spp. and Zinnia spp. (However, some of these like zinnias may do better if planted later-June). If the weather is chilly, wait to put in heat lovers such as Aster, Celosia (cockscomb), dwarf Dahlia, periwinkle (Vinca spp.), Portulaca spp. and Zinnia spp. Zinnias are usually available in May. Heat loving plants planted too early may be set back if cool weather sets in, and they may never do as well. If you have already planted some of these, or want to and you have extra space, you may want to plant some now and later. D.Bulbs, corms, tubers-Plant in containers or beds, tuberous begonias, caladiums, callas (Zantedeschia spp.), Canna spp., Dahlia spp., Gladiolus spp. (With glads I suggest you plant a new block every 2-4 weeks to have them available over a longer period, I have had them in bloom as late as December), lily (Lilium spp.-many species), montbretia (Crocosmia crocosmiiflora & Titonia spp.), tigridia, tuberose (Polianthes tuberosa) and Watsonia spp. E. Groundcovers: It’s a good time to plant them. However, you may want to avoid those that are invasive, which spread over large areas rapidly, and are not easily trimmed back. Even annuals can serve as good ground covers. However, avoid those that grow and produce seed rapidly, and grow like vines. Weeding these out, where you don’t want them can become a chore. See me for suggestions, or others that have preferences for ground covers. F. Vegetables and herbs- Plant or sow seeds of beans, carrots, corn, cucumber, eggplant, lettuce, peppers, radish, squash and Swiss chard. Leave garden space for subsequent sowings 2-3 weeks later-of bush beans, beets, carrots and radishes. Toward the middle of April, is a good time to plant eggplant, melons, peppers and tomatoes. They require warm weather. G. Tomatoes: Bertolero recommends planting tomatoes between April 15 and May 15. However, tomatoes are the one vegetable that most of us plant that we might enjoy vine ripened tomatoes. As such, John Chiapelone suggests that you plant them now if the weather is favorable and let them get off to an early start. If the weather turns cool after planting and they don’t do well replant them. Planting them in 5-10 gallon containers or larger and filling with potting soil is the most practical system, and you can move them into the warmest spots to encourage good growth. Also, using potting soil avoids the development of problems with fungi and nematodes for which resistant varieties labeled VNF are recommended. If planted in your vegetable garden plot, sooner or later you will likely have a severe problem of verticillium wilt. The fungus is found on several native weed species, and if you have planted potatoes (something like 50% of commercial potato seed (tubers) are infected with verticillium and certain other vegetables. As such, they can introduce the fungus into your garden soil. This allows you to select varieties that taste best and do best in your specific area. Wire tomato cages are available, and can be placed over the plants to allow the vines to grow upright. However, several of our members have constructed their own cages using a wire mesh 6 X 6 inch squares, from a 6 foot wide roll, which is available at places like Orchard Supply. You also need a 3/8- ½ inch rebar (reinforcing bar) or equivalent to hold the cage upright. To set fruit, nighttime temperatures shouldn’t drop below 55°, (SM County Times, March7,’’99). Tomato varieties: (Burlingame Garden Center’s-newsletter March, 2001 gave the following recommendations for best tomatoes for the peninsula). They were Early Girl-earliest to bear, and best tomato in our area. Ace-the best all purpose. Brandywine-excellent heirloom tomato. Produces meaty, real tomato tasting fruit. Beefmaster & Better Boy-best in hot areas. Celebrity-large fruit, takes about 80 days. Good tasting. Champion-large fruit, early producer. Red Cherry & Sweet 100-good in salads and hors d’oeuvres. Patio-excellent in containers. Red Pear Roma-great for sauces. San Francisco Fog-thick skinned fruit, but will produce in cool temperatures. Yellow Pear-good for cooking and preserving. Bush Early Girl-a bush variety of the popular Early Girl; Golden Boy-a round yellow low acid tomato, good for salads; Oregon Spring- an early tomato for cool summer seasons, exceptionally fine flavor and succulence; Patio-excellent in containers; Pearson-medium size, old favorite, needs heat; Sweet 100 -tiny red tomatoes on a strand, good for munching and salads. Sunset claims Early Girl can’t be beat for flavor and production in cooler climates. On the last page of this April In Your Garden, I have abstracted from SF Chronicle, 3/1/08, parts of 2 up-to- date articles on this subject. H. Herbs-nurseries should have many herbs in 6 packs. While it’s cool, you may want to speed-up your very warm weather vegetables by planting them with hot-caps, or at least cut slits in pieces of clear plastic (PE) drop cloths and plant through the slits. The clear plastic warms the soil. Such plastic is available in the paint section of stores. You may even want to do this for cucumbers, eggplant, melons and peppers where you plant or seed through a slit in the film. An expansion of this will be found under IRRIGATION on page 7
Citrus and other tender perennials-After the danger of frost is past; is when you should plant tender plants such as citrus, fuchsias, Bougainvillea spp. and others. Plant these as soon as possible so they have this early growing season to get established. Plant them in protected sites, such as against a south-facing wall or under an overhang, or grow them in containers and move the containers to a protected area in winter. You might even be bold and try, Hibiscus spp, Jacaranda, Mandevilla spp., Mexican lime (Key lime), Pandorea spp., and Plumeria spp. However, keep in mind that such perennials are somewhat risky to grow in Northern California, if the above are not properly considered, since severe freezes usually kill them. As such be prepared to protect them if frost is expected. If you are considering planting citrus, you may want to check with a reliable local nurseryman and also get his advice on varieties.
Lawns and ground covers-Mild weather is ideal for starting cool season lawns (bluegrass, fescue, rye, and bent-grass) from seed or sod. The lawns may be direct seeded or use grass sod. If you use sod, have it done by a reputable sod company. Sod is best for lawn grown on slopes. It’s still a good time to repair any worn or bare spots in an established lawn. You can also plant a ground cover now to replace lawns. If you seed your lawn, Don Burns recommended the tall fescues, which are drought tolerant. There are several, including a fine bladed dwarf ‘tall fescue’. Several year’s ago, I found only one nursery with dwarf tall fescue. However, some nurseries appear to have a single supplier of grass seed. Again, if you are considering planting a lawn (cost considerd), I prefer a direct-seeded one. However, if you are planning to sell your home and your lawn is not the best, a green healthy looking newly sodded lawn can help sell your home.
Soil Preparation and fertilization: An adequate supply of oxygen and water are the 2 most essential needs for both plant and animal life. Denied either for a sufficient period of time, death occurs. Optimum conditions for plant growth is a soil with about ¼ air as air space, ¼ soil moisture and ½ soil in good tilth. The addition of organic matter like compost will degrade and create humus, which in turn helps create well aggregated soil with larger pores, allowing better movement of air into the soil. This is the principal reason why organic matter should be incorporated into the soil each year. When the above is properly managed then the next most important need is proper plant nutrition. This requires the recognition of the differing needs of different plants to promote growth, and for flowering and fruit production. For established perennials, early spring is a critical time to fertilize. Roots are actively growing and it is important that a good supply of nutrients is available. Also, the winter rains have usually leached out much of the nitrogen (N) and in most cases at this time the fertilizer applied should be high in N. There are many fertilizers on the shelves, numerous brands, and special mixes of NPK (nitrogen, phosphorous, and potassium), for almost every type of plant. Some include minor elements. The mixtures for specific plants and plant groups vary somewhat, and between brands but their ratios of NPK are based on frequent use during the growing season. Some of the mixtures for plants such as for orchids have 2 different NPK percentages, high N during the growth period, and low N for flower development. As such I would suggest that you might want to apply additional N such as ammonium sulfate, on this first application this spring. After that you may choose to use the special mixes for the rest of the season. Above, I referred to fertilizers that contained minor elements. Also, with annuals, we have an opportunity to till the soil by various means, and we can do things differently, as indicated above. However if you have used the 16-16-16 type frequently in the past, nitrogen N alone, applied, as ammonium sulfate may be quite adequate, and may be preferred, because excessive use of phosphorus can drastically reduce the population of mycorrhizal fungi. These fungi are symbiotic, that is although they feed off the plant, their spider web mycelium (root-like) forage a far greater portion of the soil than the plant roots for plant nutrients, than the plant can do by itself. As such this mycelium functions as a greatly expanded root system for the plant. Also, the mycorrhizae are far more efficient in the uptake of certain needed micronutrients. It is recommended that you spread compost or other organic soil amendment 2 to 3 inches deep on the surface; also sprinkle over the surface, ammonium sulfate 21-0-0, or 16-16-16 or comparable fertilizer (follow application rates on the label). Use a spade or a rotary tiller to turn it into the top 6 to 8 inches of soil. Level the surface with a rake, plant, and water well. If you have good soil to about 12 inches deep, double-depth-spading should result in even better plants. The key here is a soil with deeper good aeration, which is essential for the best plant growth. Our past rains can compact the soil and good tillage plus incorporating compost or the equivalent corrects this.
Subsequent Fertilization: Apply a regular or high-nitrogen fertilizer every 4-6 weeks or make a single application of a controlled-release fertilizer as prescribed on the label. Also, feed established lawns, citrus, roses, fall-planted trees, shrubs and ground cover. Where practical, if you haven’t already applied a controlled release fertilizer like Osmocote, do it now. Azaleas, Camellias and Rhododendrons, and many ornamental perennials have two somewhat different feeding times as a general rule: when the flower buds plump up, use a high P, low N mixture, then just after bloom a high N mixture. Nutrients, particularly N, is used extensively by the plant for growth, but N leaches out of the soil in containers quickly, so you’ may need to feed those plants more often, (about every two weeks) with half-strength fertilizer, or incorporate a controlled-release fertilizer into the potting soil when potting or repotting. This is may be good for the entire season.
Fertilization-general: Many papers and nursery newsletters comment on the loss of nutrients from excessive rains, actually the primary nutrient lost is nitrogen (N), but the P & K should move down farther into the soil. This suggests that the first fertilizers applied should be high in nitrogen. Also, the controlled release fertilizers such as Osmocote are very good to use in areas where subsequent scheduled fertilizing will be a challenge to your time available and memory of when needed. However again, plants that are preparing to bloom and an extended bloom period require a fertilizer high in phosphorous (P) A. Azaleas, Camellias and Rhododendrons including Hydrangeas feed with an acid fertilizer (purchase bags or boxes of dry fertilizer for acid loving plants). Plants that prefer acid fertilizers usually do poorly in alkaline. I know that alkaline soil can favor the build up of ‘water molds’ which can kill roots of most of these plants, and the most susceptible varieties can die. However, most of our group’s soils are either neutral or slightly acid. Also, continual application of considerable N usually results in increasing the soil’s acidity. B. Roses-if you haven’t already applied your slow release fertilizer, like Osmocote, Apex or others, and the alfalfa pellets or meal to stimulate the development of new canes, do so now. Also if you have previously experienced aphid problems apply Bayer’s 2 in 1 systemic Rose & Flower Care. C. Lawns- apply fertilizer every 6 weeks, and one high in N. Application of a fertilizer with a pre-emergent herbicide to control quack grass, spurge and other annual weeds. D. Cymbidium and other orchids: I would recommend you use GROW MORE PREMIUM ORCHID FOOD, which has replaced the 2 Rod McLellan brands at OSH. Use instructions on Grow More’s labels are as follows: Feed cymbidiums with 30-10-10 (NPK) RED during the growing season (February thru October). To help initiate flower spike feed Cymbidiums with 6-30-30 BLUE during the dormant season (September through February). Use 20-20-20 YELLOW as a general purpose feed for all cattleya, vanda, and dendrobium and other orchids year round. Use 20-10-20 GREEN , Urea free formula for paphiopedilum, phalaenopsis and others year round. E. Citrus- apply monthly, and one (chelated with iron (Fe) when needed), but when chelated iron is needed, foliar sprays of a Miracle-Gro formulation or its equivalent should give the best results, F. Hydrangeas-spring application of aluminum sulfate (acidification of the soil) for deeper blue flowers of the old varieties. Some of the new hybrids don’t require this. G. Citrus and other fruit trees-application of N, such as ammonium sulfate is essential as bloom occurs to assure a good set of bloom. Use about 1 pound per 100 sq ft.. After bloom is over, and the fertilization of hundreds of blossoms has been completed there is a very great need of N to promote growth. H. Azaleas, Camellias. and rhododendrons: During or after bloom is over, there is need for N to promote growth. I. Plants in general: Actually most plants when actively growing should be fertilized at least once a month, unless a controlled release fertilizer formulation is used. Trees are an exception, for which 3 applications per year is a common recommendation. However even here, slow release fertilizers and even fertilizer stakes may be used successfully but these are considerably more expensive for large trees.
Special maintenance care: Rhododendrons-Gently snap off rhododendron blooms as they fade. Be sure not to damage the tiny leaf buds immediately below the flower clusters; these small buds represent upcoming summer growth and next year’s blooms. If the faded blooms don’t bother you, by waiting until they start to dry, may allow for easier removal. Actually, I found that Anne Berkyto’s use of small pruning shears better. John Chiapelone suggests for a bush that is large as you want it to be, you should consider pruning, which may even give you more blooms. Camellias remove fading and diseased camellia blooms to minimize petal blight. Azaleas and their blight is somewhat different than camellias and if the appearance of the dead blooms doesn’t bother you, just leave them as is.
Grooming: A. “Dead Heading” is the practice of continually removing fading blossoms from plants to maintain good blooming. With most plants, blossoms ultimately produce seedpods. This is the plant’s natural way of perpetuating itself. If the faded blossoms are not removed, they will usually produce seed and frequently the plant will stop blooming or at least substantially reduce the amount of blooms. Almost as much as to say I’ve done my thing for this year. However, many of the new hybrids produce very little seed, and may not require deadheading as such, but the faded blooms may be unsightly. Roses are prime examples of the need for deadheading. Their large seedpods, “rose hips” use much of the plant’s photosynthesis production during their development, and when pods are numerous, flower production is drastically reduced. Most of the annual flowers perform best when deadheaded and flowers are continually cut for flower arrangements in your home. Fortunately there are flowers like impatiens that don’t require this and continually bloom profusely. As ‘a rule of thumb’, most annuals that produce viable seed will produce many volunteers from the fallen seed, the next year, and in certain areas of your garden you have a built-in replanting system. My own Greek poppies in my yard are examples of this. However, if they grow where you don’t want them, just consider them weeds and dispose of them. If you would like some in other areas of your garden, transplant them, but only select the very small plants without flower buds. B. Groom and feed spring bulbs-Remove spent flowers where the stems rise from the base. Leave foliage to manufacture and store food reserves for next year’s show, and feed with a bulb fertilizer high in P (phosphorus). When the leaves start to yellow, cut back on water. If you make a practice of digging them up, this is a good time to dig and store them for next year. Even better, if you have them in pots, move them to another location where their appearance doesn’t matter.
Compost: Creating a compost pile is an excellent way to recycle lawn clippings and other leafy garden debris by transforming it into a rich organic soil amendment. Its incorporation into your soil will improve subsequent plant performance. Some suggest that you layer vegetation with thin coverings of soil, keeping the pile moist, and add a handful or two of a high nitrogen fertilizer (ammonium sulfate) for every 18-24 inches of depth, this speeds up the decomposition. To further speed up the composting process, turn the pile every week or two. However, this is only necessary if you need the compost right away. Otherwise, just let it decompose slowly.
Maintenance: Dig or hoe weeds? Dig out deep-rooted weeds such as dandelions, oxalis, etc., with a hand weeder, trowel or screwdriver. To make certain you get the entire root, slip the tool into the soil and pry up the taproot. You can hoe out all types of annual weeds produced by seeds, when they’re small by cutting just below the soil surface with a sharp hoe, hula hoe or cultivator. To prevent them from surviving on nighttime dew, hoe in the morning so the sun bakes the weeds or rake them up and place in the compost, if they haven’t gone to seed. About this time of year, in some cases it is too late to effectively prevent weed seed from germinating using pre-emergent seedicides, because most seeds have germinated. Lawns and crabgrass control are exceptions, because with the intensive irrigation and fertilization, seed production and germination continues.
Prune: A. Frost damage- After new growth appears, prune out any frost-damaged wood on temperature sensitive plants, such as bougainvillea, citrus and others. This is needed this year in the colder areas here on the peninsula. B. Flowering shrubs and trees- Also, prune to shape spring-flowering shrubs, ornamental flowering trees (after bloom) and overgrown hedges. Finish pruning deciduous fruit and ornamental trees if new growth hasn’t emerged. Most deciduous fruiting trees and plants should be pruned before the leaf buds begin to swell and leaf out, but a late pruning is usually better than no pruning. Prune flowering peach, plum, etc. after bloom and while faded blooms and fruit spurs (blossom source) are still conspicuous. Shape them by pruning lightly but thin out where they are overgrown. Camellias like other blooming perennials are best pruned for shape after blooming. Other ornamentals to prune or pinch: fuchsias (prune/pinch and remove twiggy growth), geraniums & pelargoniums, hydrangeas, flowering-vines such as clematis, wisteria, shrubs such as lilac and Japanese snowball and shade trees after they bloom. Roses-if you pruned in January or early February, you should have good new growth. Now is the time to prune or rub-off new shoots growing into the center of the bush or rubbing against each other. Good air circulation is needed to keep rose diseases at a minimum. Also, watch carefully for shoots coming up from the rootstock, if left to grow, they will usually restrict the growth of the very rose variety you selected and planted. Ultimately they can takeover completely and you will have only the rose variety of the rootstock, which usually doesn’t contribute much to your rose garden. Fuchsias: (After frost) prune back, because they only bloom on new wood. Basket fuchsias are cut back to the edge of the fuchsia and may look somewhat like a ‘hat’ at the top of the plant. Stake again leaving only 5-6 main stems. Bush fuchsias are cut back from 50-80% to get a good start. You should start feeding them every 2 weeks. Keep pinching the new growth each week to make the plants branch out. If you let them bloom too soon, that branch won’t grow anymore, so pinch until they are the size you want-usually until about May, and then let them bloom. Continue your fertilizing, if you haven’t used a controlled release form.
Propagation: Seeds -Those plants you wish to plant, but are unavailable in your nurseries you may need to plant from seed. Cuttings- The young tender tip growth of most perennials root best, most of the soft wood plants do not even needing a rooting hormone.
PEST CONTROL
Slugs and snails are on the attack now. Pick by hand, or use traps or baits. If you have pets that might eat the bait, there are formulations that for the most part eliminate that problem-check the labels. Earwigs can also be a problem and effective baits are available, but sometimes hard to find.
Sucking Insects: A. Aphids-you can hose them off with a nozzle on the end of a hose. Also, a good practice, where applicable is to apply a fertilizer-systemic insecticide. I recommend Bayer’s 2 in 1 systemic Rose & Flower Care. It also lists other insects that eat holes in the leaves that may also be controlled. If you haven’t done so, treat your roses and other aphid prone small bushy ornamentals now. Many aphid species are primarily active during the spring cool weather and only feed on the tender new growth. Aphids are also somewhat unique insects, on roses they initially fly in as winged adult females, and subsequently give birth to young aphids. Ants are frequently associated with many sucking insects, and some recommend keeping them off trees and shrubs, including camellias, citrus and roses, by wrapping the trunk with a 1 to 2 inch wide strip of masking tape, and then coating it with a sticky barrier usually available in nurseries. Reapply when the barrier gets dirty. However, the control of the ants themselves is to keep them from carrying the young aphids. Also, they will do the same thing with scale or other sucking insects. I have observed ants carrying scale from a different plant to an anthurium that I placed in my greenhouse. I appreciate their presence, because they tell me that there is a fair population of some sucking insects present, which I haven’t observed. Most sucking insects produce a honey-dew when feeding on plants, and to which the ants are attracted and on which they feed. I may not have observed the specific pest, but the presence of ants is usually indicative of their presence. As long as the ants don’t get into the house, particularly the kitchen, I welcome their presence as indicative of a serious problem. B. Scales are another type of sucking insect which you should check for on your potted plants and trees. My cymbidiums in the past have periodically had a scattered scale problem. In the past I have used an old tooth brush to brush the scale off the leaves. Ann Berkyto successfully uses rubbing alcohol to clean any scale off of her orchids. Another friend has been very successful using Bayer’s 2 in 1 systemic Rose & Flower Care. I followed her practice and have since never observed any scale. C. Spittlebugs should start to appear now. They are reasonably well controlled by washing off the plants (adding a tsp of dishwasher detergent per gallon of water helps). They are only a problem usually around the first of spring, for about 1-2 months, and if their appearance doesn’t bother you, you needn’t do anything. However, if you have used Bayer’s 2 in 1 systemic Rose & Flower Care, it should take care of the spittlebugs. D. Yellow Jackets: If you are bothered by yellow jackets in the summer, now is the time to put out traps. They start breeding in the spring. E. Oak moths: they may have already done their damage, if not spray with possibly some of the new synthetic pyrethroids. However, I stopped spraying for them, because the damage to my oaks was minimal, and it became even less of a problem after I stopped spraying. I was probably killing the moth’s predators or parasites.
Codling moths are the most serious pests of apples, pears and walnuts: A. Apples- April is normally the beginning of the cover sprays for codling moth and if you want relatively worm free apples, you should start planning your program. Codling moth-traps & control: (traps contain a female pheromone that attracts the males to the traps and away from the females). Some suggest that you use two traps per apple tree for moth control and install before bud break. It can reduce the moth population by luring the males into the trap. However their cost is relatively high and with high populations of moths (your neighbor’s), they usually give inadequate control. The University of California has demonstrated their inadequacy. If you can justify the cost of a single trap, it might be better used to determine moth flights into your tree(s), indicating when to spray. One entomology text (1951) reports that most eggs are laid 2-6 weeks) after apple bloom and hatch within 6-20 days. The worms feed slightly on the leaves but in a few hours crawl to the young apples and chew their way into or enter the fruit, frequently by way of the calyx cup at the blossom end. One University of California recommendation was to spray when 90% of the petals have fallen (this should be April or May for most varieties), or when traps indicate post-bloom moth activity. If you haven’t already started, start now; apply (carbaryl) Sevin, at rates designated on the label. Sevin is very toxic to bees and should not be used when bees are active pollinating, but at that time bee activity should be negligible. Note egg hatch occurs 6-20 days after eggs laid. The 2nd spray is recommended 25 days after the first spray, again with Sevin and a 3d spray in late June, using the same chemicals as the 2nd spray. All non-chemical biological controls usually require 9-15 sprays. Even the newly refined oils require 4-6 sprays, and applied to kill the eggs, not the larvae (worms). Keep in mind that the adults of worms are moths, which will fly in from the surrounding neighborhood, especially where your neighbors don’t maintain an effective spray program. There can be as many as 3 generations of codling moths per season. The worms (larvae) from each generation will emerge from the apples, and crawl down the tree trunk and pupate in the debris in the soil surface. The pupae hatch out as moths and fly back into the tree, starting the cycle again. If a band of corrugated cardboard is wrapped around the trunk, the larvae will crawl into the corrugations. These must then be disposed of before the pupae hatch out as moths. This will reduce each subsequent generation. A point on moths vs. butterflies, which are closely related, is their flight habits. Moths are predominantly nocturnal, meaning they are most active at night. You are aware of moths being attracted to lights at night. Butterflies are generally more active during the daytime. As such you are not likely to see moths flying around your apple tree during the day time.
IRRIGATION
Drip Irrigation with Timers: There are at least 3 reasons for using a timer for automatic irrigation.
A. As we get older, the more that can be pre-scheduled without our having to rely on memory, the better.
B. Although initially, installation will take some time, long term you will be saving yourself time and money.
C. You may have time to water manually but what do you do when you are gone for a week or two? D. During periods of drought and water rationing, water usage can be reduced almost 75% to a ‘survival level. If you want to install 1 or more timers and you would like some guidance, please discuss it with me. As for drip irrigation, micro-sprinklers, etc., I recommend them in most situations except lawns. Conventional and improved spray heads are still the best on lawns.
18. Drip irrigation with mulch film: For years I have emphasized the above. However, in reviewing The Vegetable Grower News, November 2004, I spotted 2 articles with many other important benefits where drip irrigation and plastic mulch have been combined. Produce brokers are now requiring drip irrigation of several vegetables planted through plastic mulch, tomatoes being one example. In a second article it listed 12 benefits to the combination of drip irrigation under mulch film.∙ Earlier crop production (7-21 days earlier); ∙ More efficient use of water; ∙ Reduced leaching (loss) of fertilizer (especially N) on lighter sandy soils; More efficient use of fertilizer inputs through fertigation technology; ∙ Reduced soil and wind erosion; ∙ Potential decrease in the incidence of disease (water molds, one example); ∙ Better management of certain insect pests (spider mites, one example); ∙ Fewer weed problems; ∙ Reduced soil compaction and elimination of root pruning; and ∙ Opportunity to double or triple crop with maximum efficiency. The crops that have shown significant increase in earliness, yield and/or quality with the use of plasticulture (PE film with drip irrigation) include muskmelon, tomato, pepper, cucumber, squash, eggplant, watermelon and okra. If any of this stimulates your interest in combining mulch film and drip irrigation, contact me after the meeting and we should be able to arrange a private session on film, drip systems, fertilizers, and all that should be needed. I have wanted to visit The Urban Farmer Store in San Francisco, and get the latest on drip irrigation supplies for the home gardener, such a request will move it up on my priority list. However, Jim Chiapelone who landscaped and installed drip irrigation in Fran’s front yard, showed me several new approaches to installing drip irrigation.
19. Check, clean your irrigation system and reset timers: Your system probably needs cleaning, but equally important is to check each irrigation outlet (sprinkler or drip system) to be certain they are functioning properly. White PVC pipe- wherever this is above ground and exposed to sunlight (direct or indirect) algae will grow inside and some will slough-off and start plugging the system. Straight chlorox applied once a year is probably the best method to solve this. I have done it several times in the past and will be glad to discuss the technique. However you should cover up the white tubing with dirt or paint it brown or black. Next program your timer for the best interval between irrigations and the best periods of irrigation. As the season warms up you may want to shorten the interval between applications.
The above references as well as each Month in Your Garden has information that I have abstracted from my files containing over 25 years of Sunset; many of the former San Mateo Times, many years of the SF Chronicle, SJ Mercury News (Don Neumann), various farm crop newsletters; Burlingame Garden Center, Carlmont & Wegman’s monthly news letters; some from OSH, Filoli, Ortho brochures, Better Homes & Garden, Don Burns, Jim Hester, various Farm Advisors, my own 62 years experience in agricultural research, and those of others, as well as miscellaneous publications. More recently I began scanning some of the same articles into my computer. Also, I appreciate your bringing articles of new information to our meetings, or sending them to me as Gordon Lavering often does. When time permits, I will scan them into my computer. You may find your own experiences don’t always agree with what I’ve presented, to which I can state, there is nothing equal to one’s own experiences, especially if you can repeat it. The successful growing of plants involves so many factors, some that you recognize, but many others for which even the experts don’t have answers.