June Garden Tips
CHECK YOUR IRRIGATION SYSTEMS NOW-- BEFORE HOT WEATHER STRIKES!
As you know, the upcoming months should bring waves of heat that can potentially stress your plants. Adequate water through the summer will assist them to thrive during these expected long, hot days. Keep in mind the following points:
- Trees and shrubs have largely been surviving on winter rain up until now.
- Lawns, trees and shrubs cannot coexist on the same water schedule.
Check your irrigation systems now for leaks and broken or malfunctioning parts. Check also for adequate coverage. You may need to add emitters on drip systems for maturing trees or shrubs or you may need to adjust the length of time the system runs. To gauge whether your plants are getting adequate water, check the depth of moisture in the soil the day following watering. Soil around trees and shrubs should show moisture to 12 inches and will not need water again until the top 2 to 3 inches of soil is dry. Adjust sprinklers so that no water spray strikes the trunk of any tree.
Check out our Care Guide on Irrigating Plants for more information.
Below is a summary for irrigating lawns; shrubs and roses; trees; and vegetables.
Ideally, lawns should be watered 1 to 2 times a week for one-half to one hour to encourage deep root systems. If the lawn slopes and the water runs off too quickly, divide the hours or half-hour into 2 or 3 periods. Also be sure to aerate (punch holes) in the lawn every year or two.
SHRUBS & ROSES
For most drip or spray systems, once a week for one hour should be adequate-if you have 4 drippers per bush with 2 gallon per hour emitters. Remember to avoid direct water on rose foliage unless you water early in the morning.
Water established trees once a month June through September for a few hours with bubblers at the dripline to ensure a deep soaking. You can also build a basin at least 4 to 6 inches deep and flood monthly. If it is more convenient, use a Ross Root Feeder to irrigate your trees once a month. If the trees are a bit peaked in July or August put 25-10-10 (high nitrogen) fertilizer cartridges in the Ross Root Feeder.
Soaker hoses work great for vegetable gardens. Run them 1 to 2 times per week for 4 to 5 hours. Turn pressure on low so that you count one drip every three seconds along the entire line.
More tips for maintaining a fabulous garden. . .
- Plant marigolds, alyssum, petunias, lobelia, cleome, salpiglossis, fibrous begonias, Portulaca, scarlet and blue sage, zinnias, bedding dahlias, cosmos, and ageratum in full sun. For the shade, try impatiens, browallia New Guinea impatiens, fibrous begonias, and coleus. Some full sun annuals will also perform decently with only a few hours of sun, such as alyssum and lobelia.
- To thwart slugs and snails after planting annuals, apply Cooke Pest Granules or Lilly Miller Slug, Snail and Insect Killer. Cooke's and Lilly Miller are equally effective all year. If you have dogs or children at home, avoid these two products and use Sluggo or Sluggo Plus which is also effective year round. Sluggo Plus contains iron phosphate plus Spinosad which makes it effective for snails, slugs, and many insects.
- Pansies and violas planted for the winter months will serve you through summer as long as they are located in dappled light or morning sun conditions.
- Sow seeds for cosmos, zinnias, marigolds, and sunflowers directly into the garden by mid-June. Seeds should sprout in 10 to 14 days.
- Wait to cut or tie the foliage of your spring bloomers until half of the leaves have turned yellow or brown.
- If you missed planting dahlias, crocosmia, calla lilies, or cannas by bulb, you will still have the opportunity to plant these bulbous perennials in the next few months. Assortments of wildly-colored dahlias, from the dwarf to the tree varieties, in 1- to 2-gallon containers have arrived. Cannas from our growers offer unusual foliage and flower colors, adding instant texture and lushness to the garden. Check out crocosmia as well, an often overlooked but colorful summer bloomer, great for naturalizing and for cutting.
- Continue planting gladiolus bulbs at 2-week intervals through July for continuous bloom. Plant bulbs about 4 times the depth of the bulb. If you plant the bulbs 4-6 inches apart, the plants will support one another.
- To help prevent thrips on gladioli, soak bulbs 2-3 hours in a weak Lysol solution (2 Tablespoons of Lysol to 1 gallon of water). You can also use Spinosad (Captain Jack's Deadbug) when gladiolus leaves are about one foot or more tall. Spray every two weeks to control thrips.
- Deadhead and feed daffodils, Dutch iris, and other long-lived perennial bulbs with Master Nursery Bulb Food when they’re done blooming. Fertilizing at this time is crucial, as they soak up the sun and store food in the bulb, all for next year’s blooms.
- When planting tuberous begonias, remember to leave about one-quarter inch of the top of the bulb exposed. Apply Master Nursery Bulb Food when new growth from the bulb emerges and again when they finish blooming.
- Fireblight has been a more serious than usual problem this year. Fireblight affects pears, Pyracantha, Photinia, apples and less seriously, loquats. A bacterial problem, fireblight appears on the tips of new growth or at the flower cluster. The plant part will be blackened as if scorched by fire or a blowtorch. The new growth tips then curl downward as on a shepherd's crook. To control, cut 9 to 12 inches below affected tissue, sterilizing pruning tools between each cut with rubbing alcohol or a bleach solution. Apply appropriate sprays during bloom next spring. (See our Apple & Pear Care Guide.)
- Blossom blight is also more prevalent this year and should not be confused with FIRE BLIGHT. The blossoms of apple, pear and their relatives are affected by turning brown and falling off. There is little or no fruit. There are no scorched tips nor do the new growth tips curl downward. Spray as appropriate next spring. (See our Apple & Pear Care Guide.)
- The first symptoms of brown rot and bacterial canker on apricots, peaches, nectarines, cherries and plums is the same as blossom blight of apples and pears (see previous paragraph). Later, there will be a dieback of and/or oozing from short fruiting spurs or branch tips and a decrease or absence of fruit production. While it is too late to spray for this disease this year, next year apply two additional sprays of Liqui-Cop or Triforine or Chlorothalonil at pink bud and full bloom. When pruning this summer or next winter, you should remove dead or oozing wood.
- Some gardeners are reporting peach leaf curl on their peach trees. Research at UC Davis states that there is no control once symptoms appear. The infected leaves will fall, and they should be collected and disposed of -- not composted. The spores for the fungus, which causes peach leaf curl will be embedded in the bark of the peach tree so your dormant spray next winter will have to be very thorough.
- To control powdery mildew on grapes, spray every two weeks with sulfur starting when the new shoots are 12 inches long. Avoid overhead water and be judicious with fertilizer so that excess soft foliage isn’t generated. The soil for table grapes should be kept moist at all times while letting the top 6 to 9 inches dry out. The soil for wine grapes should dry down 18 to 24 inches between waterings.
- Scab of apple and pear appears as black or brown spots on the leaves and black or brown depressions on fruit. Scab is caused by a fungus and generally begins to show in April and May. If scab is present on apples this season, spray apple trees next season at 2-week intervals. Use sulfur or Liqui-Cop or Micro-Cop. If scab is present on pears this season, spray next dormant season with sulfur or copper and at the 'green tip' stage and again at early bloom.
- If fruit trees seem chlorotic (yellow leaves with green veins), foliar feed with Liquid Gold at the rate of 2 Tablespoons per gallon of water at two week intervals until symptoms disappear. Treating the soil once or twice a year (Valentine's Day and 4th of July) with Iron Sulfate may be a more permanent solution.
- Wait to thin fruit until after the June drop, when trees undergo a natural self-thinning period.
- Fertilize deciduous fruit trees and vines around Memorial Day and Labor Day with Master Nursery Fruit Tree & Vine Food. Don’t be tempted to over fertilize, as this can cause secondary problems with some fruits. If you missed the Memorial Day fertilizing, do it now!
- If apple and pear trees have woolly apple aphid, which appear as a white cottony substance, usually in crevices, pruning cuts and on the ground at the base of the tree trunk, spray with Malathion or Sevin.
- To prevent sunscald paint deciduous fruit tree trunks with a white, water-based interior latex paint that has been cut 50% with water. This is especially important for new trees and trees planted in blazing hot locations.
- To keep birds from raiding cherries and other fruits, cover trees with plastic bird netting. Fasten the netting around the trunk to keep it from blowing away and to slow down attacks by squirrels.
- Select and plant citrus now.
- Citrus should be pruned to remove dead wood, crossing branches or long water sprouts. Suckers from below the graft should be pulled off, not cut off. All cuts should be made where the water sprout or branch main stem or lateral branch.
- Citrus should be checked for scale, a sucking insect that usually clusters along fruit stems, new growth and the undersides of leaves. If scale is found, the U.C. Farm & Home advisor recommends that scale be sprayed with a mixture of horticultural oil and malathion. Three applications are necessary at two-week intervals. Never spray horticultural oil more than 4 times during the growing season or when daytime temperatures exceed 85 degrees F. Ants running up and down the trunk often indicate the presence of scale, so look carefully, as more than one kind of scale may be present. Check also for snail damage.
- Fertilize citrus in March, May, July, and September with Master Nursery Citrus Food.
- While most folks prune their fruit trees once a year during the dormant season, a light pruning during the summer can benefit the home orchard in two ways. First, summer pruning helps to maintain the size of your trees. By reducing canopy mass at this time, trees grow at a slower rate. Second, you can encourage secondary branching on long whips. This increases fruiting wood. In contrast, winter pruning tends to shape trees, remove dead and dying wood, and strengthens and increases fruiting wood. Finally, when the canopy is opened more light helps the fruit to ripen.
- Groundcovers can still be planted, but watch for those occasional June hot spells and be sure to water new plantings in full sun deeply every 3-4 days. Erigeron, Convolvulus, creeping Rosemary, Ceanothus and Manzanita are excellent groundcovers for hot, dry locations (though they do need water while becoming established). Vinca major, mahonia repens and creeping snow berry will work in a shady area.
- Fertilize groundcovers with Formula 49 two times a year, in May and September.
- To ward off slugs and snails, bait with Sluggo or Sluggo Plus(safe for pets and people) or one of the products listed for the ANNUALS.
- Apply Bayer Advanced Lawn Season-Long Grub Control or Beneficial Nematodes now to control cutworms, lawn moths, Crane flies and other lawn pests. (Note: If you are using herbicides to control weeds in your lawn, allot 2 weeks before and after nematode applications to encourage their populations to grow). Controlling insect larva now will reduce the incidence of skunks and raccoons tearing up your lawn in the fall. Beneficial nematodes are microscopic organisms which consume various destructive soil-dwelling insect larva (grubs) and will not harm earthworms or bees as opposed to the Bayer product.
- Spread seed or lay sod through June. For details on preparing an area for lawn installation, check out our Care Guide on Lawn Preparation. Sod orders placed with Wegman’s usually take 2-3 days for delivery. Call us for details!
- Feed lawns with Master Green Lawn Food or Master Green Weed & Feed. For organic products use Dr. Earth Lawn Fertilizer or Concern Weed Prevention Plus.
- If you have had problems with Bermuda grass in your lawn, apply Turflon Ester, which also controls annual and perennial broadleaf weeds in established lawns. For crabgrass and some other weed grasses, as well as a host of other tenacious broadleaf weeds, use Trimec.
- For oxalis and broadleaf weeds, use Turflon Ester, a liquid that can be sprayed over entire lawns. Because oxalis is so tenacious, two applications may be needed.
- It's time to set mowers to summer levels: 2.5 to 3 inches for fescue and bluegrass lawns and 1.5-2 inches for Bermuda grass lawns. Remember: You cannot use pre-emergent products for 3-4 months prior to seeding a lawn or laying sod. You can, however, use Round-Up 3-4 days before seeding or laying sod. Before installing pick up or print out our care guide referred to above.
- Grass-cycling means to leave your grass clippings on the lawn after mowing. The grass decays and disappears within three or four days and reduces fertilizer use by 30 to 50 percent.
- Be sure to deadhead as blooms fade to ensure continuous bloom throughout summer.
- Check out yarrow, nemesia, penstemon, lavender, verbena, and coreopsis for the sun, and Chinese foxglove, campanula, Filipendula, Hostas, bacopa, and heliotrope for the shade.
- Spittlebugs generally make their homes on perennials and shrubs this time of year, looking literally like a wad of spit nestled in the leaves. Spray off with a hose or spray with Master Nursery Nature’s Pest-Fighter or Safer Insect Killing Soap. These are the larva of leafhoppers, a sucking insect.
- A nice handful of sun-loving perennials double as both deer-resistant and drought-tolerant plants: lavender, yarrow, the salvias, echinacea, sea lavender, society garlic, penstemon, and brachycomb all provide excellent summer color in addition to these practical attributes.
- To enhance a tropical look or as accents near a pool or stonework, plant some of the new Cannas: "Tropicana" has green, pink, red and yellow-striped burgundy foliage and bright orange flowers. Others include "Black Knight" and "Miss Oklahoma".
- Fertilize perennials in February, May and September with Master Nursery Rose and Flower Food, Formula 49 or Dr. Earth Rose & Flower Fertilizer. You can skip fertilizing in May if your garden consists of perennials which thrive on neglect. Many of the drought tolerant perennials (see above), for example, prefer not to be pampered with high nitrogen, high phosphorus fertilizers.
- To control Bermuda grass and crabgrass and other weedy grasses in ornamental beds, try Trimec or Turflon Ester.
- Bait now with Sluggo Plus or Master Nursery Pest-Fighter for Slugs & Snails. Especially vulnerable are perennials such as columbine, hosta and delphinium.
- Be sure to stay on top of deadheading for continual bloom!
- The inevitable aphid can be controlled by blasting off with water or by spraying with Safer Yard & Garden Insect Killer, Safer Insect Killing Soap, Malathion or Sevin. If you use oil, do not apply more than 4 times during the growing season. Wait at least 2 weeks between applications. Oil may damage leaves during hot spells.
- Watch for katydids and cucumber beetles, both of which chew on flower buds, leaving holes in flower petals. Spray as for aphids (see above) or with spinosad (Captain Jack's Deadbug) but do not use Safer Insect Killing Soap.
- Rose weevils and curculios chew holes at the bases of buds then lay their eggs within. When larvae hatch, they eat their way through flower buds and petals. The only control for these pests is to disbud plants as if deadheading.
- Rose slugs have become a problem. They initially feed on the underside of rose leaves causing "windows". Eventually, the leaf looks like a piece of lace. Spray with Safer Yard & Garden Insect Killer, Sevin or Malathion. Captain Jack's Deadbug is totally organic and works well for all chewing insects.
- You may also notice activity by leaf cutter bees, which remove neat, semi-circular notches from the margins of leaves. Disregard this insect: these notches are harmless and the leaf cutter bee is extremely beneficial in the garden. She uses the piece of leaf for nesting purposes.
- Powdery Mildew appears as whitish splotches on the surface of leaves and on buds and stems. To control, use Safer Garden Fungicide or wettable sulfur. If these measures aren’t satisfactory, use Ortho Garden Disease Control (Chlorothalonil) or Ortho Rose Pride (Triforine).
- Rust appears as small yellow to black spots on the upper surface of leaves, which, when flipped, show rust-colored pustules. Use the aforementioned products to control.
- Black spot normally appears in early spring as large, dark irregular marks on the upper surface of leaves. Cool, wet weather provides a favorable environment for the spread of Black Spot. With the advent of warm, dry weather it will not spread further unless you overhead water. Spray with Ortho Rose Pride (Funginex) before it shows up. Pick off all of the infected leaves and dispose of them. DO NOT COMPOST.
- Prevent weeds in rose beds by applying Concern Brand Weed Prevention Plus. This product is corn gluten, which prevents seeds from germinating and contains 9% nitrogen, providing a slow-release fertilization. Never use Round-Up within 100 feet of roses; it's the surest way to deform new foliage and developing buds. You should hand-dig or use a tool such as a hula-hoe to remove unwanted weeds.
- Rub off leaf buds that are facing the center of the plant. This will redirect growth to outward growing buds and help keep the center of the rose open for air circulation. Watch too for sucker sprouts below the graft union and remove as needed by pulling or breaking off; NOT by pruning off.
- Prune once blooming climbers such as Cecile Brunner, Belle of Portugal and Lady Banks roses--after bloom.
- Continue monthly feedings with Master Nursery Rose & Flower Food. For an organic alternative, apply Dr. Earth Rose & Flower Fertilizer, which contains alfalfa meal, every other month. Alfalfa meal contains the chemical triacontanol, which spurs the formation of new canes. If you do not use an organic fertilizer, supplement your regime with alfalfa meal every March and July.
SHRUBS & VINES
- Azalea gall appears as swollen leaves with white powder on them. Remove by pruning, do not compost but dispose with your garden trash. Next spring, as new leaves begin to emerge, spray with copper (Liqui-Cop).
- Watch for thrips and black vine weevil on rhododendrons. Thrips damage appears as a mottling or bleaching of the upper surfaces of leaves. Undersides show small, glossy black dots. Weevils leave distinctive notches along leaf margins as they feed. Both can be controlled with Sevin, Malathion or Spinosad.
- If your gardenias show brown buds which drop off before opening, the cause is probably thrips. Use Malathion, Spinosad or Sevin.
- Fuchsia gall mites create gnarled leaves with reddish blisters and are inevitable on hybrid fuchsias. If symptoms appear, U.C. Davis recommends that you prune out disfigured growth and spray with Sevin once a month after spring pruning. You can also begin a preventative program using Sevin once a month. Consider species fuchsias, which are mite-resistant. While not as showy as the hybrids, they offer the same bloom time and a surprising diversity of foliar textures. Fuchsia gall mites are spread by humming birds and being blown by the wind. (See Fuchsia Care Guide.)
- Camellia golden ring spot virus manifests as yellow rings or circular splotches on 2-year old or older leaves. It may also cause streaking in flowers. There is currently no cure for this virus, but it may spread by pruning tools. Be sure to clean tools with alcohol or a 10% bleach solution between shrubs.
- Deciduous clematis are in full bloom. Excellent in part to full sun, rampant and colorful, these vines simply require that their roots be kept cool. Mulch freely with bark, Forest Blend or Gold Rush or plant under the edge of a deck or at the foot of a tree or shrub. Mr. Ed has created a nice effect by planting clematis to grow up among star jasmine, which hides an old fence. The clematis can be left there year round or cut to the ground in January.
- Mediterranean climate natives now in bloom include Sollya, Protea, Leucospermum, Grevillea, and Correa. While you may not be familiar with these plants, they make excellent additions to the landscape with their early bloom, deer-resistance, and tolerance to wet winters and dry summers.
- Passion vine, bower vine and scarlet trumpet vine bloom now through mid-summer and make nice companions to potato vine, which blooms all summer. Passion vine will also bloom all summer.
- Fertilize evergreen shrubs and vines in May and September with Master Nursery Formula 49 (8-4-4).
- If your azaleas and camellias have been troubled by petal blight, which appears as brown splotching on petal margins of open flowers, partly open flowers and flower buds, keep beds free of debris. Remove infected flowers and buds and try not to let infected petals hit the ground. If they do, gather and place in trash immediately, do not compost! Azalea petal blight can be controlled by spraying but not camellia petal blight.
- Watch for powdery mildew on crape myrtles. If symptoms appear, spray twice with sulfur a week apart. If you’re thinking of planting crape myrtle, consider planting those with the Native American tribal names, such as Tuscarora, Hopi and Natchez. These varieties were hybridized specifically to resist powdery mildew. Crape Myrtles bloom best in full, hot sun (best south of Belmont on the Peninsula).
- For established trees that are isolated in the landscape or for those trees which seem chlorotic, use the Ross Root Feeder to fertilize and deep water.
- If the tips of leaves on your Japanese maples turned brown along the edges last year, protect them from tip burn this year by spraying with the anti-transpirant Cloud Cover and mulch 2-3 inches deep. Remember to always keep mulch at least 3 inches away from tree trunks.
- You can still plant tomatoes, peppers, eggplants, squash, corn, basil, green beans, cucumbers, and melons from starts. Remember to amend soil liberally, as vegetable crops deplete nutrients from soils rather quickly. We like Gold Rush, which includes chicken manure, giving plants a quick nitrogen boost. Add Master Nursery Tomato and Vegetable Food at planting time and six weeks later.
- Start beans and pumpkins from seed as late as mid-June.
- We have tomatoes available in 2 inch; 4 inch; 1 gallon and 5 gallon containers, many with fruit already formed.
- If you have had problems with verticillium wilt on tomatoes and potatoes, consider covering beds with clear plastic for 6-8 weeks during the months of June to September. This process, known as solarization, sterilizes the soil by cooking harmful microbes in the soil. Be sure to anchor the plastic with dirt or heavy objects. While these beds will be unusable for a season, the sacrifice will pay off in healthy plants the following year.
- For whiteflies on tomatoes, use Safer Tomato & Vegetable spray, three times at three day intervals. Consider using whitefly traps in conjunction with the sprays for more complete control and even a "Dustbuster" late in the afternoon to vacuum up the reproductive adults. Mr. Ed has found that spraying with Safer Insect Killing Soap until it drips off the plant will get a lot of them.
- Tomatoes make great container plants. Use at least a 15-gallon container for most types and try Sweet 100s in a 16 inch hanging basket.
- Plant artichokes through June and July from 4 inch or 1-gallon pots.
- Cool season greens, such as lettuce, spinach, cilantro, chard, and mustard can be planted through the summer in morning sun locations. Under warmer temperatures, they will go to seed more quickly, so plan on planting more frequently.
- Grow herbs in one gallon sized containers in full sun for strongest flavor.
- Plant basil and cilantro at 4 week intervals to maintain a continuous supply.
OTHER THINGS TO DO
- Spread 2 to 3 inches of mulch over garden beds. Mulch materials can include fir bark, 'Forest Blend' redwood compost, composted leaves, or Gold Rush, to name a few. In general, mulches are any organic material spread over the surface of the soil that serves to retain moisture, discourage weeds, moderate soil temperature and add organic matter as it breaks down. Be sure to keep mulches 2 to 3 inches away from the crown of plants and trunks of trees.
- Consider utilizing beneficial insects in lieu of insecticides this summer. Ladybugs and their larva feast on aphids and are especially useful in rose gardens and vegetable gardens. Release 50-100 at a time, in the evening. Set out shallow dishes of water along with plant parts covered with aphids. These props will encourage ladybugs to stick around since they don't fly at night. Praying mantids are sold in their egg cases. Set out egg cases in a shady location off the ground, such as in a tree or shrub. Eggs will hatch mid- to late summer. Beneficial nematodes are useful for lawns, shade gardens which include rhododendrons and around citrus. Apply April/May and again in July. Soak in bucket of water for 30 minutes, and then gently remove vermiculite. Put solution in watering can and water lawn or beds, applying as evenly as possible. Rinse out bucket to get all organisms. As all of these are living creatures, remember not to apply insecticides in their midst, as they will be killed.
- Container plants must be fertilized monthly with an appropriate granular fertilizer such as Formula 49.
- Don't forget your birds, which eat their weight in bugs each week. They need a drink of water, too, so keep the bird bath or shallow dish full. If you rinse these containers out once a week, there will be no mosquito problem.
- Consider watering indoor plants with 2 Tablespoons of vinegar per gallon of water once a month in order to reduce salt build-up and to lower pH.
- Compost tea, formerly known as manure tea, is regaining popularity. You can make your own by filling a 5 gallon pail one-third full of Master Nursery Steer Manure and one-half a cup of Master Nursery Fish Emulsion. The pail is then filled with water and allowed to 'steep' for 4 to 7 days. At the end of 'steeping,' the mixture is filtered through a couple of layers of cheese cloth or an old T-shirt. The 'tea' is diluted to the color of weak tea for use by watering a gallon or so of it around each plant and spraying it on the foliage. There is some experimental evidence indicating that spraying the 'tea' on plant leaves prevents attacks by disease micro-organisms. Some people put the manure teas steepage in an old pair of tied off panty hose and use them like a teabag. Be sure to wear rubber gloves during these procedures because instances of bacterial infection have been reported from handling these products and their resultant 'tea.'
- Sharp pruning tools make clean cuts that heal quickly. Check out our Pruning Tool Renovation service, which includes cleaning and sharpening and replacing missing parts. If you are unsure whether we can service your tool, bring it in for assessment.