September Gardening Tips

September is our transition into fall. The nights begin to cool off more so than in the earlier summer months, but the days are still warm and we often have bouts of extremely hot weather and Santa Ana winds. Over the next few months, we switch from summer-blooming to winter-blooming annuals and from warm-season to cool-season vegetables. You will slowly transition into this change by cleaning out disheveled flowers and vegetables. Be sure to leave the good ones in place for as long as they will last. If you did not sow seeds for transplants in August, you can do so now.

What to Plant

  1. Now is the time to prepare the soil to begin to plant. Don’t worry about rushing; October is generally the best month for planting. Good soil produces healthy plants.
  2. Fall Vegetables – Right now is the time to start fall and winter vegetables. Plant or seed them directly into the garden or start them indoors. Green onions, carrots, beets, lettuce, spinach, radishes, and over-wintering cauliflower are the most popular vegetables to grow in the winter garden.
  3. Herbs – Plant perennial herbs such as mints, French sorrel, Roman chamomile and comfrey.
  4. Perennials and Biennials – Many plants can be started from seed, sown directly into the garden this month. Iris and other early-blooming perennials can be divided this month. Choose a cool day or time of day, and give them a tall drink of water in their new locations.
  5. Bulbs to plant now – Tazetta hybrids should be planted now. These polyanthus or bunch-flower daffodils include paper whites, golden Dawn, Soleil d’Or and Matador. Also plant drought-resistant bulbs and corms from South Africa such as freesia, sparaxis, ixia, tritonia, watsonia and nerine.
  6. Bulbs to plant later – Daffodils, anemones, ranunculus, Dutch iris, muscari (grape hycinthia), tulips, spring-blooming crocus and hycynthia should be brought home and stored in a cool dark place. Most of these should be planted in November except for the tulip, crocus and hyacinths which need to be refrigerated for 6 to 8 weeks before planting. For inland areas; start chilling in October for December planting. For coastal areas; start chilling in November for January planting.
  7. Peas – To have Sweet peas by December plant them now. – Both bush & vine types, from seed. Use quality seeds by Stover®, Lilly Miller® or Ferry-Morse®. Look for “early flowering” varieties. Spring or summer flowering types won’t bloom until the days are more than twelve hours long. To speed germination, soak seeds overnight before planting. Plant peas such as snow peas, snap peas and English peas. Provide a trellis for vines to climb.
  8. Prepare to plant – Cooler, wet weather will be upon us before you know it. Plan & start to plant permanent landscape plants, shrubs, trees & cool-season lawns. Prepare to plant or repair your lawns with Grangetto’s Tall or Dwarf Fescue Lawn Seed. One pound covers 100 square feet. Top dress with Kellogg® Topper to keep seed bed moist.
  9. Remove heat loving annuals such as marigolds and fill them with cool season annuals! Amend the soil for later planting with Gardner & Bloome® Soil Building Compost. Plant winter annuals such as pansy, snapdragon, stock, larkspur, Iceland poppy in full sun. In shady spots plant primrose, English daisy, cineraria & cyclamen.
  10. Plan to plant wildflower seeds before a heavy rain. This may mean waiting until mid or late October. Stover® Seed has a variety of quality wildflower seed mixes that will bloom beautifully! Scratch the surface of the soil with a heavy rake, scatter the seeds, top with a lightweight potting soil and keep moist until germination.

Harvest Time

  1. Harvest late fruits and veggies daily. Remove warm-seasoned vegetables badly damaged by pests, diseases or past their prime production periods. Prepare the soil for planting your cool-season vegetables. Use a good planting mix to mix into the native soil. You might also consider mixing in a good organic pre-plant fertilizer, high in phosphorus. When to harvest
Feeding and Maintenance


  1. 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. Try Ironite® Mineral Supplement.
  2. Warm deason 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.
  3. Fall is a good time to aerate your lawn
  4. Control insects in lawns with Bayer® Complete or use Monterey® Lawn & Garden Spray for an organic control.

Plants, Trees and Shrubs

  1. TRIM BACK – Fall is the time to trim back overgrown plants. Mulch around everything if you haven’t.
  2. THIN OUT heavy shade trees before Santa Ana winds blow. One way to help your trees survive strong Santa Ana winds is to reduce turbulence by pruning. The idea is to thin your dense trees by opening areas so that strong winds can blow through without damaging limbs.
  3. PRUNE – Summer-blooming shrubs with a good set of sharp pruners, but wait to prune spring-blooming shrubs until after their bloom period. Prune cordon and espalier apples if you have not already done so and if shoots are mature enough.
  4. LIFT & DIVIDE agapanthus, daylily, clivia, Shasta daisy, gazanias & ornamental grasses as many of these become crowded after a few years in the ground & blooms decline.
    With a serrated bread knife, cut large clumps into two – four smaller pieces. Replant immediately & follow with a deep soak
  5. LIFT & DIVIDE perennials such as Blanket flowers, bugleweed, creeping Jenny, spotted dead nettle, spurge, stonecrop, wormwood and arum. Angle your spade or shovel at a 45 degree angle at the drip line and cut down and under the clump from various points around the outer edge until you are able to lift the plant out of the hold.
  6. TREES & SHRUBS – Use Bayer® Dual-Action Tree & Shrub on permanent landscape plants, trees and shrubs to provide a slow release feeding and protect against insects.
  7. 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 veggies. Use Kellogg® Amend or Gardner & Bloome® Soil Building Compost to rejuvenate your soil. Consider adding some Gypsum for really damaged soil. You can start planting cool-season veggies now.
  8. HERBS – Prepare soil and plant perennial herbs such as mints, French sorrel, Roman chamomile and comfrey.
  9. FRUIT TREES & VINES – Continue thorough irrigation to maintain adequate soil moisture until winter rains begin. Prune out dead and severely damaged shoots of deciduous trees before foliage drops. Continue to protect fruit from birds and yellow jackets. Harvest fruit as soon as it ripens.
  10. DECIDUOUS FRUIT TREES – Do not fertilize deciduous fruit trees. Cut off the suckers from deciduous fruit trees.
  11. ROSES – Water is still very important this month. Watch for days of dry, hot heat and be sure to water adequately. Remove dust and grime weekly with a strong spray of water over the entire rose bush. This is great for removing spider mites. You can also use Green Light® Rose Defense to help combat these pests and many other products are available. Fertilize roses this month with Dr. Earth® Organic Rose & Flower food or try a multi-action fertilizer to combat pests as well, such as Bayer® Advanced Rose & Flower Care. This should be your last feed for this years growing season as the roses will try to go dormant after October’s bloom period.
  12. ANNUALS & PERENNIALS – Clean-up and remove heat loving annuals to prepare for cool season annuals. Continue cleaning up bloomed out perennials. With some plants, this not only makes them look neater, but it also often encourages a fresh flush of growth and/or bloom. Lift and Divide perennials such as Blanket flowers, bugleweed, creeping Jenny, spotted dead nettle, spurge, stonecrop, wormwood and arum.
  13. PLUMERIAS – The weather is still warm and plumerias are growing strong. Fertilize growing plumerias once a month with low nitrogen, high phosphorous plant food, using one tablespoon per gallon pot. Try Gro Power® Flower N’ Bloom 3-12-12. 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!
  14. BEGONIAS – Feed tuberous begonias this month. Water sparingly. Do not allow plants to dry out or keep them too wet.
  15. CACTI & SUCCULENTS – Watch warm season plants and fertilize less as they go dormant. Feed all container-grown succulents with a well-diluted complete liquid fertilizer. Winter growers will need more fertilizer and water as they start to grow. Look for signs of growth as the seasons change. Transplant growing seedlings and rooted cuttings now so they can become established before winter. Prevent pests from becoming a major problem. Inspect plants for mealy bugs, mites, aphids and snails. Treat as needed.
  16. CAMELLIAS – July was the last of your three annual fertilizer applications. Now you will fertilizer with a 3-12-12 fertilizer such as Gro Power® Flower N’ Bloom each month through January for extra large buds. Keep well watered this month, but not too soggy. Letting them go dry will cause the buds to drop off, depriving you of their beautiful blooms. Some varieties of camellias form a great many more buds than they can support and so will naturally drop buds. They naturally-dropped bud will be green whereas a water-stressed plant will drop brown buds. For the largest flowers, you can start "disbudding" camellias now by removing all but one flower bud from each cluster. Be careful not to remove the growth bud. Growth buds are thin and pointed; flower buds are round and fat. Watch for aphids and hose them off with a spray of water.
  17. HYDRANGEA – If you want to maintain a “blue” hydrangea or change your hydrangea’s color, you need to start now; once they start developing buds it’s too late. Not all hydrangeas can be made blue. White varieties always stay white and some pinks turn purple instead of blue. The color can be modified by adjusting the pH of the soil. A pH of 4.5 – 5.0 yields blue flowers, a pH 5.5 – 6.5 yields mauve, and a pH of 7.0 – 7.5 yields pink. Use a soil test kit to test the soil pH. Sulphur or aluminum sulfate can be used to lower soil pH. Use Grow More® Blueing Formula according to label direction.
  18. IRIS – Clean up iris beds. Cut off damaged leaves, remove debris and mulch beds. Plant new iris you may have purchased. Iris blooms come in a breathtaking rainbow of colors and combinations of colors. Their unique shape sets them apart from other flowers. Irises are heavy feeders. Fertilize at least three times a year and you can foliar-feed in between as well. Iris should be divided about every three to five years.
  19. FERNS – Keep removing old fronds from ferns. Water frequently as most ferns are in full growth now. Fertilize with half-strength, high-nitrogen liquid or slow-release pellets. Protect your plants from the sun.
  20. BROMELIAD – Continue to 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.
  21. DAYLILIES – Continue to clean up daylilies by removing stems that have bloomed. The stems on most daylilies go brown after flowering; simply yank these off. Don’t try to yank off the stems that stay green and continue to grow. 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.
  22. FUCHSIAS – are looking bloomed out and shabby. 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.
  23. PELARGONIUMS – Flowers are still at their peak this month and will be through October. Continue with your fertilizer schedule. Generally fed every 2-3 week during the growing season. Do not let plants dry out. Water in early morning or early evening for best water retention.
  24. ORCHIDS – Now is a good time to switch from your “growing” season fertilizer (spring through summer) to a lower nitrogen, higher phosphorous & potassium fertilizer to encourage development of bloom spikes. If your orchid leaves are dark green, chances are that they’re in too much shade. Bring them out into more light until their leaves turn a yellowish color.
  25. 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® 13-4-12 Palm K. Remove only dead and dying foliage from date palm.
  26. 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.
  27. NATIVE PLANTS – Cut back native plants to control their size and also in areas that pose a fire threat. Start to plan your native garden for fall/winter planting. More information can be found at Las Pilitas Nursery
  28. 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!


  1. There’s still a month of warm weather. Wait until next month to re-adjust timers. Better yet, install a new Weather Based Controller that will adjust your water based on the real-time weather reports! Speak with a Grangetto’s Representative to learn more about the water saving irrigation devices.
  2. Make sure citrus trees are watered adequately during this month. If the roots go dry, the result can be split fruits
  3. Water lawns, ornamentals and vegetables.
  4. Be sure to follow your local watering restriction and guidelines

Pests to Watch out For

  1. 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.
  2. 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.
  3. Yellow Jackets - Rescue® Yellow Jacket Trap or Victor® Yellow Jacket Trap
  4. 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!
  5. 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.
  6. Squirrels – Use Havahart® Traps, Protecta® Bait Stations, Wilco® Squirrel Bait and Station or Squirrelinator® Multi-Trap.
  7. Mosquitoes – Use Mosquito Dunks in ponds or standing water to help control mosquitoes.
  8. 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.
  9. Snails & Slugs – Use Organic Gro Power® Slug N Snail, Organic Sluggo® Plus, Original Sluggo® or Corry’s® Snail & Slug Meal or Pellets, or Copper Banding.
  10. Aphids – Control aphids with insecticidal soap and beneficial insects. Safer® Insect Killing soap is a good organic choice.
  11. 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.
  12. Scale – Use Lilly Miller® Superior Type Spray Oil or Ortho® Volck Oil Spray to control crawlers.
  13. Lawn pests – Use Bayer® Complete or Spectracide® Triazicide for a conventional method. Use Green Light Lawn® & Garden Spray with Spinosad for organic control.
  14. Vegetable Pests - Use Green Light Lawn® & Garden Spray with Spinosad or Sevin® Insect Killer Liquid or Sevin-5® Dust.
  15. Rats & Mice – Use Just One Bite® Rodent Baits..
  16. Gophers – Use Wilco® Gopher Getter or Cooke Quick Action Gopher Mix to rid your yard of gophers. Use ZP® Bait in and around garden beds.
  17. Caterpillars – Use Safer® Caterpillar Killer, Monterey® Garden Insect Spray or Green Light Lawn & Garden Spray with Spinosad. Look these pests on your broccoli and cabbage!
  18. Whiteflies – Whiteflies Bayer® Advanced Tree & Shrub Insect Control
  19. Rose Pests – Use Bayer® All-in-One Rose & Flower Care, Bayer® 3-in-1 Insect Disease and Mite Control or Green Light® Rose Defense.
  20. 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.
  21. 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.
  22. Fireblight – Remove disfigured branches & twigs
  23. Weeds – Use Bonide® Crabgrass Preventer or Bayer® Season Long Weed Control in lawns. Use Green Light® Amaze in ornamentals & flower beds. To control weeds in lawns while giving them a good feeding use Lilly Miller® Ultra Green 28-2-3 Weed & Feed. For non-selective areas, use Roundup ®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.

Grangetto's Garden Club feature of Grangetto's Farm and Garden Supply | Powered by: Garden Center News