August Gardening Tips
It’s August and we are feelin’ the heat in So Cal! Believe it or not, August is the month to prepare for the fall. “Already?” some might say. Here’s why we start now for fall. August is the best time to plant seeds for annual and biennial flowers and cool-season vegetables. The warm soil makes it perfect for seed germination and by October, the prime fall planting time, the seedlings will be ready to transplant into your garden. Other reason to plant now; biennials and perennials that normally bloom the second year in cooler climates will bloom their first spring in Southern California.
What to Plant
- Sow seeds of cool-season vegetables, towards the end of August, such as broccoli, Brussels sprouts, cabbage, cauliflower, celery, kale, kohlrabi, mustard, lettuce and other greens and edible-pod peas. Plant radishes, carrots and beets directly into the garden.
- Start biennials from seed this month. It is best to sow biennial seeds in mid-summer so that the plants will develop during the summer and fall. After exposure to the winter cold, they will develop flowers in the spring. Try foxglove, Canterbury bells and hollyhocks.
- It’s best to wait until late in the month to start cool-season annuals from seed unless you plant them in pots for later transplanting. Cool-season varieties include calendula, cineraria, dianthus, delphiniums, Iceland poppies, nemesia, pansies, snapdragon, stock, sweet peas…. to name a few.
- This is the month to select fall bulbs for planting. Design your garden now, rather than waiting till the last minute.
- Continue to plant tropical plants in coastal areas.
- Continue to plant succulents, cacti, and euphorbias.
- This is a good time to choose crape myrtles. Most varieties are into their bloom period and you will be able to select the perfect colors for your landscape.
- Pick out and purchase cassias and flame eucalyptus.
- When planting in containers, hanging baskets or raised beds use Gardner & Bloome® Potting Soil.
- Plant bearded iris rhizomes in areas that get at least a half-day of sun. In hot inland areas, lightly bury rhizome tops to prevent sunburn. Closer to the coast, plant rhizomes so the tops show slightly above the soil surface.
- Plant a warm season lawn for better drought tolerance. AmSod® Tifgreen Hybrid Bermuda uses up to 30% less water than fescues. The St. Augustine variety is aggressive, low growing and the most shade tolerant. Learn more at from AmSod
- TIP: Seed germination in hot weather; keep seed flats in semi-shade and cover with plastic till seeds germinate. Remove plastic and gradually move into increasing light over a two to three week period until they’re in full sun.
Harvest Time
Harvest your summer vegetables as soon as they are ready. Don’t let them rot and drop to the ground. This can bring insects and cause disease. Watch out for watermelon-size zucchini; Fast-growing cucumber, squash, and zucchini plants can be harvested almost daily. See when to harvest.
Feeding and Maintenance
Lawns
- Cool season lawns such as fescue, bluegrass, and perennial ryegrass are growing slowly now, so they need less frequent mowing. Perennial ryegrass and bluegrass should be cut at about 2 inches. Tall fescue should be cut a little higher, 2 to 3 inches. Remember these grasses grow slowly during the summer so little or no fertilizer is needed. Feed cool-season lawns only if they show signs of yellowing.
- Warm Season Lawns such as bermuda, zoysia & St. Augustine are growing at their fastest now; they thrive in the warm summer heat. This means they need more frequent mowing. Bermuda and zoysia should be cut short, 0.5 to 0.75 inches. Cut St. Augustine to 2 inches. All warm season grasses should be watered deeply and infrequently to encourage deep root growth.
- Feed warm-season lawns with Best® Iron Supreme 16-4-4 every 4-6 weeks during the growing season for fast green-up. For a longer, slow release fertilizer use Best Super Turf 25-5-5. Best Super Turf lasts for 12 weeks for a continued feed and green lawn. For an organic food, use G&B Organics Lawn Food.
- Control lawn insects such as fleas and ticks with Bayer® Complete Insect Killer
- Control lawn fungus such as dollar spot or brown patch with Bayer® Fungus Control for Lawns.
- The best prevention for these types of infections is to aerate often, reduce shade to effected areas, and follow a fertilization schedule to help prevent fertilization with excess amounts of nitrogen.Learn more about lawn diseases from UC Davis IPM
Plants, Trees and Shrubs
- BENEFICIAL INSECTS such as the almost decollate snails, praymantis, ladybugs, etc. keep other insect pests away from your vegetable gardens by eating aphids, scale, and other annoying intruders. You can use beautiful flowers to tempt these garden friends into your garden. Try putting some of these flowers near to your rose garden for aphid control!
- VEGETABLES – Cover planted seeds with floating row covers to protect young plants from insects. Continue to harvest your veggies as they mature. Make sure not to let old veggies and fruits stay rotted on the plant or ground for long. It will only bring insect and disease. Prepare beds for cool-season planting. Use Gardener & Bloome Soil Building Conditioner to rejuvenate your soil. You can sow some cool season veggies from seed this month directly into the garden. Sow others into starter trays. Grangetto’s Speedy Root Plant StarterTrays are great for this.
- HERBS – Continue to deep water plants such as basil, mint, Yerba mansa, Gota kola, horsetail, comfrey and other water-loving herbs. Do not overwater herbs such as rosemary, lavender, sage, thyme and aloe. Dry bundles of oregano, thyme, sage, lemongrass, raspberry leaf, feverfew
- FRUIT TREES & VINES – Continue to monitor soil moisture within the root zone and irrigate when soil begins to dry at a depth of 3 to 4 inches. Apply enough water to leach salts below the plant roots periodically. Support limbs that have a heavy fruit load. Harvest fruit as soon as it ripens. Remove all rotting fruit. Keep ants off trees by wrapping with heavy paper around the trunk and apply tanglefoot. You can use >AntPro Bait with station to wipe out whole colonies of ants.Inspect new leaves for signs of iron and zinc deficiency (yellowing between the veins). Apply a micro-nutrient if needed. Prune out blackberry and raspberry canes that have borne fruit.
- DECIDUOUS FRUIT TREES – Do not fertilize deciduous fruit trees. Cut off the suckers from deciduous fruit trees.
- ROSES – Water is very important during the hot summer months. Be sure to water at least three times a week, more often if temperatures exceed 84 degrees. In very hot weather, roses can lose water faster from the leaves than they are able to draw it up from the roots. If you see wilting, this is a sign that your roses are not getting adequate water. Deadhead summer blooms and prune. Cut the stem far enough down to support the next rose. Usually 1/3 of the bush to promote a good fall bloom.Roses also consume food faster in hotter weather. In extremely hot weather growth is slowed considerably and less food is needed. Read the package directions for feeding. Try Organic G&B organics Rose & Flower food. Use Monterey Neem Oil to control pest, insects and disease.
- BEGONIAS – Begonias are in full bloom now. They are heavy feeders so feed them regularly. Remove dead leaves, old flowers & other debris. Pot rooted cuttings in light porous soil. Check for disease and pests. Let them dry out between watering and remove spent blossoms.
- PLUMERIAS – Fertilize growing plumerias once a month with low nitrogen, high phosphorous plant food, using one tablespoon per gallon pot. Gro Power® Flower N’ Bloome is a good choice. When planting cuttings that have calloused over for at least three weeks, use quick draining soil such as cactus mix. Water well once, then do not water or feed until leaves are about one inch long.For established plants, water when no moisture is present on the top two inches of a container, water until it runs out the bottom. Don’t use an under dish. Give plumerias full sun. Your plumerias may have some beautiful blooms now!
- BIENNIALS – Fertilize biennials started from seed in July with fish emulsion at weekly intervals.
- ANNUALS & PERENNIALS – When annuals or perennials get leggy or scraggly, consider cutting them back by one-third or more. With some plants, this not only makes them look neater, but it also often encourages a fresh flush of growth and/or bloom.
- FUCHSIAS– start to look bloomed out and shabby by August. Cut them back lightly, pinch the tips for a week or two and you’ll get another flush of blooms that will last till the cold weather sets in. Cuttings from this new growth will root quickly. Continue to feed with a high phosphorus fertilizer.
- DAHLIAS – Cut old blossoms back to the first leaves of the main stalk to prolong blooming. Disbud to encourage better blooms. Tie canes to prevent plants from breaking. Spray for insects and mildew. Continue to control snails and slugs. Fertilizer with a 5-10-10 fertilizer or similar.
- PELARGONIUMS – It is still necessary to avoid pruning or cutting. Continue to remove dead or damaged leaves to prevent molds and fungus. Continue to watch for geranium rust. Use Immunox® to treat. Immunox® is a non-sulfur based product. Keep the soil moist and the foliage dry. Apply a good fertilizer at two-week intervals. Use one-third to one-half recommended strength. Protect from sun. Protect plants from severe sun damage.
- FERNS – Most ferns are in full growth now. Water frequently. Remove old fronds. Use a slow release fertilizer or half-strength, high-nitrogen fertilizer. Watch for snails and slugs. Use Monterey® Sluggo® if needed. Protect from hot sun.
- CAMELLIAS – If you forgot to give your camellias their third feeding last month, do so early this month. A good annual schedule of feeding is three times a year. March should have been your first feeding. You gave them more food in May and you should have fed them again in July. Try G&B Organics or Lilly Miller® Camellia and Azalea Food. Watch for aphids and hose them off with a spray of water. Keep well watered, but not soggy. Inconsistent watering is the reason for bud drop during the bloom season.
- HYDRANGEA – After hydrangea flowers have faded, cut back each stalk to two buds. New wood will spring from these to bloom next year. On young plants, do not cut back any green stem that haven’t bloomed yet for these will bloom next year.
- BROMELIAD – Protect bromeliads from burning during the hot weather by making sure they have enough shade. You can do this with shade cloth. Propagate bromeliads by cutting off pups when they are one-third to one-half the size of the mother plant.
- IRIS – Dig over-crowded clumps. Divide and prepare to plant rhizomes. Refresh your prepared beds for planting. Use amenities such as fertilizer, peat moss, compost, gypsum and new topsoil in beds. Mix the soil well and let bed stand for about a week before replanting. Iris can remain out of the ground three weeks or more before replanting. Plant rhizomes with the top quarter showing above the soil line. Trim the roots back to one-half inch. They will send out new roots within a few weeks. New beds need plenty of water. Irises are heavy feeders. Fertilize at least three times a year. Foliar-feed in between if you wish.
- CACTUS & SUCCULENTS – Many plants are in their growing season but winter growers like aeoniums will curl up unless watered. Cacti are desert plants, but succulents are not. Succulents tolerate and sometime prefer light shade, especially in inland areas. Use a forceful spray of water to remove aphids and mealy bugs.
- PELARGONIUMS – Avoid unnecessary pruning but continue to remove dead leaves. Watch for geranium rusts if humidity is in the forecast for several days. Use Immunox® to treat. Deadhead as soon as blooms pass their peak. Do not let plants dry out. Water in the early morning or early evening for best water retention. Some plants will stop blooming if allowed to dry out. Fertilize with an all purpose plant food every 2-3 weeks when they are actively growing. Use a synthetic insecticide if budworms should be a problem. Protect plants from sun.
- ORCHIDS – Protect from sun. Protect sensitive cloud forest orchids from heat and dryness by watering more often and providing more shade. Fertilizer steady as plants are in active growth. Add more moss to mounted plants that show signs of dehydration. Wrinkled yellow leaves are a sign of dehydration. Protect from pests such as scale, aphids, cottony mealy bugs, spider mites and other sucking insects by using an insecticidal soap such as Safer® Insecticidal Soap.
- IRON DEFICIENCY? – Many have asked us what is causing yellowing in the leaves of their citrus, camellias, and gardenias. Iron deficiency. Do the leaves near the top of the plant have green veins but yellow in between the veins? Time for either a foliar spray or a soil drench such as Grow More® Iron Chelate or Ironite® Mineral Supplement. This will help return those leaves to green!
- NATIVE PLANTS – Many established natives need little or no water during summer months but most are happier being watered once or twice a month. Spray the landscape by hose, it mimics a summer storm and washes the leaves. Mulch around plants with shredded bark or gravel.
- PETUNIA – Cut back your petunias in mid-August to keep them flowering.
- WISTERIA – Prune and train wisteria.
- DAY LILLIES – Clean up daylilies now by removing stems that have bloomed. The stems on most daylilies go brown after flowering; simply yank these off. However, on some varieties, the stems stay green and continue to grow; don’t try to yank these off. After these green stems have finished flowering, they sprout leaves and form plantlets. Once these pups have formed one or two short roots, cut off the stems. Gently snap off the pups for planting.
- TROPICALS – Continue with a fertilizer schedule for your tropical plants. Tropicals do best when feed during the growing season (spring through fall). This will depend on your schedule and type of fertilizer used. We suggest with Gro-Power® Premium Palm & Tropical Plant Food 9-3-9 or Apex® 13-5-8 Palm Plus. Remove only dead and dying foliage from date palms
- TREES & SHRUBS – Continue your fertilizer routine. There are many products available in both organic and conventional style feeding. Continue to prune your ornamental shrubs for hedges.
- ATTRACT BIRDS – Attract a variety of birds to your yard with KAYTEE® Brand Bird Seed and bird feeders. Place some hummingbird feeders around your yard to keep them coming back. Then relax and listen to the birds.
- HEALTH & SAFETY TIP – With hot weather abundant this time of year; schedule your gardening for early morning and late afternoon when the air is cooler and the sun not so intense. Be sure to use sun block when working for prolonged periods.
- MULCH, MULCH, MULCH – If you haven’t already, apply a layer of mulch on flower beds and around trees and shrubs 2-3 inches around the base of plants. It reduces weeds, conserves moisture, and prevents disease. Great stuff!
Watering
- Watering is the major chore from now until fall. Except for some California natives and a few other drought tolerant plants, everything in the Southern California garden needs regular watering. With the hot dry weather, it’s time to look at your watering practices:
- Irrigate thoroughly, long and deep but not frequently. Too frequent irrigation encourages roots to grow close to the surface where the soil dries rapidly and is subject to the extremes in temperature.
- Use sprinklers, soakers or drip systems; a thumb clamped over the end over of the hose is not going to cut it. If you water less frequently but for longer intervals, you force the water deeper in the soil where less will be lost to evaporation while encouraging deeper root growth.
- Reset your irrigation timer to water more frequently as the weather starts to warm up. Adjust as needed should we be so lucky to get adequate rain fall.
- Check irrigation systems. Fix clogs and broken sprinklers. Adjust spray heads. Begin watering as weather warms. Apply a fresh layer of mulch to conserve moisture. On drip irrigation systems, flush filters and headers
- Vegetable gardens and most flowering plants need about one inch of water every week (not everyday) to keep them green and looking nice. Be sure to water thoroughly and deeply each time you water.
- Trees (non-citrus) and shrubs will need deep soaks once each month in the summer, and regular irrigation in between. Citrus & Avocados need regular weekly watering. Allowing them to dry out can result in considerable fruit drop. If you don’t have a irrigation system consider installing one for ease of use, time and efficiency.
- Give your trees, shrubs, and perennials an occasional hosing down from top to bottom to wash off dust and pests. Use a Gilmour Flexogen Hoses paired with a DRAMM® RainWand or DRAMM® Revolver Spray Gun. Be sure that whichever type of hose attachment you choose to use, it is equipped with a shut-off valve to save water.
- Established California Natives only need deep infrequent watering during this time of year. Some natives enjoy the occasional spraying off with a quick blast from the hose. Always follow your specific plants label instructions.
- Warm season lawns should be watered deeply and infrequently to encourage deep root growth.
- Cool-season lawns should be water more frequently and not so deep.
- Water in the morning when it is still cool, so there will be less water lost to evaporation and so the lawn will not remain cool and damp overnight (and attract fungus or algae).
- Houseplants will need to be watered more often this month, especially if they’re in a sunny window.
- Check outdoor container plants every day during hot weather and about every second day in more moderate weather. Water them thoroughly each time you water.
- Be sure to follow your local watering restrictions and guidelines
Pests to Watch out For
- Ants – Ants are on the move with warmer weather. Grants Ant Stakes, Terro Liquid Ant Baits provide either indoor or outdoor control. For quick and easy removal of ants and other insects, use Terro Ant Killer spray. Use AntPro Bait & Station for large outdoor areas. Use Tanglefoot for to control ants on trees.
- Lawn Fungus– watch for lawn fungus as the weather gets hotter. Never water in the evening as this can cause fungus to grow. Use Bayer® Fungus Control for Lawns to prevent and control.
- Yellow Jackets – Rescue® Yellow Jacket Trap or Victor® Yellow Jacket Trap
- Control indoor & outdoor pests -To control insects like spiders, fleas and ants, use Bayer Complete Insect Killer. It controls insects in lawns & around homes so they don’t come inside!
- Animals – Warmer weather brings out animals such as skunks, raccoons and opossums. Trap them with Havahart Traps. We carry a large supply and they are very effective.
- Squirrels – Use Havahart Traps, Protecta Bait Stations, Wilco Squirrel Bait Station, Tomcat Squirrel Bait or Squirrelinator Multi-Trap.
- Mosquitoes – Use Mosquito Dunks in ponds or standing water to help control mosquitoes.
- Rabbits – protect your vegetables and herbs from foraging rabbits! Use Rabbit Scram Repellent to keep rabbits away. This repellent is natural and organic and works as a barrier so it never has to touch your plants.
- Snails & Slugs – Use Organic Sluggo® Plus, Original Sluggo® or Corry’s® Snail & Slug Meal or Pellets.
- Aphids – Control aphids with insecticidal soap and beneficial insects. Safer® Insect Killing soap is a good organic choice.
- Thrips – Wash foliage with water from a garden hose. For stronger infestations use Bayer® Advanced Tree and shrub Insect Control. This is a systemic that gives 12 months of control.
- Coddling moth larvae – Spray walnuts with Sevin when nuts are about the size of a nickel and again three weeks later to control coddling moth larvae.
- Scale – Use Summit Year Around Spray Oil to control crawlers.
- Lawn pests – Use Bayer® Complete or Spectracide® Triazicide
- Vegetable Pests – Use Monterey Garden Insect Spray with Spinosad or Sevin Insect Killer Liquid or Sevin-5 Dust.
- Juniper moths – Spray junipers and Italian cypress for juniper moths.
- Rats & Mice – Use Tomcat Rodent Bait, and Bait Stations
- Gophers – Use Wilco® Gopher Bait
- Caterpillars – Use Safer® Caterpillar Killer, Monterey® Garden Insect Spray. Look these pests on your broccoli and cabbage!
- Whiteflies – Whiteflies Bayer® Advanced Tree & Shrub Insect Control
- Rose Pests – Use Bayer® All-in-One Rose & Flower Care, Bayer® 3-in-1 Insect Disease and Mite Control or Monterey Neem Oil
- Powdery Mildew – Especially near the coast, this is the time we begin to see powdery mildew on our rose foliage (and other plants too). There are several different foliar fungicidal sprays to that can help. Consider Bayer® Insect Disease and Mite Control or Ortho® Rose Pride are good conventional use products. Use Monterey E-Rase® for organic growing.
- Powdery Mildew on Grapes – Apply a sulfur spray such as Safer® Garden Fungicide.
- Fruit Tree Pests – Use Monterey® Garden Insect Spray to combat caterpillars and other listed pests on fruit trees, vegetables and ornamentals. It is OMRI listed for Organic Use too.
- Tomato Hornworms – Those of you growing tomatoes and peppers, watch for tomato hornworms. You may hand-pick them from your foliage or you can use an organic pesticide formulated for caterpillar control.
- Lawn Weeds – To control weeds in lawns while giving them a good feeding use a Weed N’ Feed.
- Fireblight – Remove disfigured branches & twigs
- Weeds – Use Bonide® Crabgrass Preventer or Bayer® Season Long Weed Control in lawns. Use Green Light® Amaze in ornamentals & flower beds. For non-selective areas, use Roundup Pro Max ®or QuickPro® products. Be sure to use a good sprayer such as Hudson® Sprayers. DeWitt® Weed Barrier Landscape Fabric prevents weeds without chemicals. It still allows air, water and nutrients to go through. Lay this fabric down before planting your gardens.
Note: All information provided is based on typical season, weather and environmental statistics. These tips are provided for information purposes only and to be used as a general guide. Products/Brands mentioned may be discontinued at anytime and not guaranteed in-stock. Grangetto’s invites you to contact us or visit one of our locations for more specific care instructions.