Seasonal Gardening & Tips

We’re blessed in San Antonio to have two great planting seasons in both spring and fall. However, planning, prepping, and planting at the right time each season can be the difference between success and failure. Example: trees and shrubs are best planted in fall in order to survive our hot summers and certain veggies like tomatoes, need early planting in both spring and fall to get a harvest before extreme temperatures set in. At Rainbow Gardens, we strive to bring you the best quality of plants along with all the information you need to make each gardening season a success!

Veggie Planting Calendar by Month

The planting dates on this calendar range from the earliest to the latest dates advisable for planting these specific veggies . You will probably get the best results by planting in the middle of the range (except when it comes to tomatoes…plant early!). Remember to always keep an eye on the weather forecast, as San Antonio weather can change on a dime! Composed by Karen Gardner, Master Gardener.

Veggie Planting Calendar by Month

The planting dates on this calendar range from the earliest (in the spring, you might need to protect from late frosts) to the latest (in the fall, you might need to protect from early frosts). You will probably get the best results by planting in the middle of the range. And remember to keep an eye on the weather forecast! Composed by Karen Gardner, Master Gardener.

Things to plant starting in Jan.:
  • Peas, shelling, sugar snap & snow: Jan. 1–Feb. 15 
  • Cauliflower transplants: Jan. 1–Mar. 15 
  • Broccoli transplants: Jan. 15–Mar. 15 
  • Cabbage transplants – Jan. 15–Mar. 15
  • Collards – Jan. 15–Mar. 25
  • Turnip – Jan. 15–May 1 
  • Radish: Jan. 20–May 1 
Things to plant starting in Feb.:
  • Beets: Feb. 1–Apr. 20 
  • Carrots – Feb. 1–Mar. 1 
  • Kale – Feb. 1–Apr. 1
  • Kohlrabi – Feb. 1–Apr. 1
  • Leeks – Feb. 1–May 1
  • Leaf lettuce – Feb. 1–Apr. 1
  • Mustard – Feb. 1–Apr. 1
  • Potato, Irish – Feb. 1–Mar. 15 
  • Swiss chard – Feb. 1–Apr. 15
  • Chinese cabbage – Feb. 1–Mar. 15 
  • Tomato transplants – Feb. 15–Apr. 1
  • Corn: Feb. 25–June 15 
Things to plant starting in Mar.:
  • Cucumber: Mar. 1–Apr. 15
  • Pepper transplants: Mar. 1–May 1
  • Squash, winter and summer: Mar. 1–May 15
  • Watermelon – Mar. 1–May 1
  • Beans, bush: Mar. 5–May 5
  • Beans, lima: Mar. 5–Apr. 20
  • Beans, pole or pinto: Mar. 15–May 1
  • Cantaloupe: Mar. 15–May 1
  • Eggplant transplants: Mar. 15–May 10
  • Southern Peas: Mar. 20–Jul. 10
  • Sweet Potato, slips: Mar. 20–May 31
Things to plant starting in Apr.:
  • Okra: Apr. 1–Jul. 1
Things to plant starting in Jul.:
  • Cantaloupe: Jul. 1–Aug. 15
  • Eggplant transplants: Jul. 1–Sept. 1
  • Okra: Jul. 1–Aug. 15
  • Watermelon: Jul. 1–Jul. 31        
  • Southern Peas: Jul. 10–Sept. 1
  • Squash, winter: Jul. 10–Aug. 15
  • Pepper transplants: Jul. 15–Sept. 1
  • Tomato transplants: Jul. 15–Sept. 1
  • Rutabaga: Jul. 15–Dec. 15
  • Beans, lima: Jul. 25–Aug. 20
 Things to plant starting in Aug.:
  • Beans, bush or pole – Aug. 1–Sept. 5
  • Cabbage transplants: Aug. 1–Dec. 1
  • Cucumber: Aug. 1–Sept. 15
  • Garlic: Aug. 1–Sept. 30
  • Squash, summer: Aug. 1–Sept. 10
  • Corn: Aug. 13–Aug. 23rd
  • Kale: Aug. 15–Dec. 15
  • Kohlrabi – Aug. 15–Dec. 15
  • Radish – Aug. 15–Dec. 15
  • Swiss chard – Aug. 15–Dec. 15
  • Turnip – Aug. 15–Dec. 15
  • Potato, Irish: Aug. 20–Sept. 10
  • Broccoli transplants: Aug. 20–Dec. 1
  • Brussels sprouts – Aug. 20–Dec. 1
  • Chinese cabbage – Aug. 20–Dec. 15
  • Carrots – Aug. 20–Dec. 1
  • Cauliflower transplants – Aug. 20–Dec. 1
  • Collards – Aug. 20–Dec. 1
  • Leaf lettuce – Aug. 20–Dec. 15
  • Mustard – Aug. 20–Dec. 15
Things to plant starting in Sept.:
  • Beets: Sept. 1–Nov. 15
  • Celery transplants: Sept. 1–Dec. 15
  • Head lettuce – Sept. 1–Dec. 15
  • Spinach: Sept. 1–Mar. 1
  • Strawberries transplants: Sept. 1–Oct. 15
Things to plant starting in Oct.:
  • Onion seed: Oct. 1–31
Things to plant Starting in Nov.:
  • Asparagus crowns: Nov. 15–Mar. 15
  • Artichoke transplants – Nov. 15–Mar. 15
  • Onion transplants: Nov. 15–Mar. 1st

Lawn Fertilization Schedule

For warm season southern grasses in South Central Texas including: St. Augustine, Bermuda and Zoysia

Lawn Fertilization Schedule

For warm season southern grasses in South Central Texas including: St. Augustine, Bermuda and Zoysia

Fertilizing your lawn on a regular schedule is your BEST defense against weeds, fungus, and insect damage!

We recommend fertilizing your turf AT LEAST twice a year, in spring and in fall. However, if your lawn is badly damaged, you may benefit from the additional feedings listed between the spring and fall recommendations. The following dates are guidelines for when to make your fertilizer applications. It’s important to keep in mind that the weather can dictate an earlier or later application time.


Try your best when applying fertilizers (synthetic or organic) to keep it on the turf as much as you can. Avoid over-spreading onto sidewalks, driveways and streets, as this leads to run off. Fertilizers with iron can stain concrete. Nitrogen and phosphorous are great for the lawn but not for our water supply.

Stay away from “weed and feed” products. You’ll end up applying either your weed control or fertilizer at the incorrect time, making it ineffective.


Late March—Late April For Spring Feeding

Grass must be actively growing to absorb fertilizer properly. After the second mowing of the season, apply a simple 19-5-9 formula for an early green-up. Rainbow Gardens’ premium lawn fertilizer is specially formulated for our region.

Mid May—Early August For Summer Feeding
(if necessary).

Apply slow-release 3-1-2 or 3-0-2 fertilizers or a liquid lawn fertilizer like Medina’s Hasta-Gro lawn food.

June—September Chelated Iron application
(if needed).

When turf grass looks yellow (iron chlorosis), use apply a granular or liquid iron supplement. Every second or third month during the warm season should be enough. Hi-Yield Iron Plus granules and Dr.Iron are two excellent choices. Stay away from Ironite……it doesn’t have much effect in our alkaline (high PH) soils.

October—November For Fall Feeding

Apply winterizing formulas for winter hardiness. Ratios vary, but make sure they are “winter” or “fall” formulas designed for southern grasses. Rainbow Garden’s 18-6-12 winterizer formula is a great choice These formulas will make lawns winter-hardy and provide for early spring green up.

Recommended lawn fertilizer formulas:

19-5-9 + minors

Rainbow Gardens Premium Lawn/Tree & Shrub Food

18-0-6 + Trace

Fertilome Greenmaker


Fertilome Greenmaker

18-6-12 + minors

Rainbow Gardens Premium Fall Winterizer Lawn/Tree & Shrub Food


Nature’s Creation organic (Manure Free)


Texas Tee organic


Medina Growin’ Green organic

Frequently Asked Questions:


What do the numbers on the bag mean?

They are the ratio of nitrogen (N) to phosphorous (P) to potassium (K).


Nitrogen is responsible for making turf green.

Phosphorous (slower-acting) promotes root development.

Potassium works to feed turf and keep it strong during drought or other stressful conditions.

What differs between synthetic and organic fertilizers?

Both organic and synthetic fertilizers contain active NPK ingredients. It’s the source from where those ingredients come from that is different. Synthetic fertilizers get their NPK from chemicals. Organic fertilizers get their NPK from naturally derived elements, like manure, biosolids, and the like.

So which should I choose? This is a decision you will ultimately need to make, but here are a few differences:

Synthetic fertilizers offer quick turn around and fast green-up as their chemical ingredients are more readily available to be used right away in the fertilization process. Synthetic fertilizers are usually less costly.

Organic fertilizers take a little longer to work as their ingredients must be naturally broken down and processed in order to be used. However, most organic fertilizers actually increase the health of your soil by improving its ability to digest and absorb the fertilizer ingredients.

Soil Testing

If you continue to have issues with your lawn, it might be time to have your soil tested. The turf on top can’t do much if the soil below is horrible.

Fungus Prevention and Treatment Schedule

For warm season southern grasses in South Central Texas including: St. Augustine, Bermuda and Zoysia

Fungus Prevention and Treatment Schedule

For warm season southern grasses in South Central Texas including: St. Augustine, Bermuda and Zoysia

Chances are if you’ve suffered from fungal or insect damage in the past and it went untreated, it most likely will rear it’s ugly head back up again. Remember that prevention along with a consistent fertilization schedule will be your best defense against any of these problems.


It’s always best to bring in samples and/or pictures so we can help you clearly diagnose the issue you are experiencing with your turf, but the following are common fungus issues we experience here in San Antonio:

Late March—May

Take-All Root Rot (TARR) is a major disease problem in St. Augustine grass that will cause the leaf tissue to turn yellow, pull loose from runner (similar to grub damage, except no grubs present in soil.) In the affected areas of the lawn, you might find both green and yellow leaf blades. Close examination (might need magnification) of the runners will reveal short, dark brown to black roots. If TARR is the problem, then an application of sphagnum peat moss is one of the best treatments for this disease problem (fungicides rarely work). Apply approximately 1 to 2 bales of the peat moss per 1,000 sq. ft. to the affected areas of the lawn and thoroughly soak the peat moss until it is wet. We have seen better results from a top dressing of peat moss than we have with the application of any fungicide in most cases. Repeat peat moss application a year or two later as needed.


Slime Mold presents itself as patches of grass, about hand-size, that appear to have cigarette ashes sprinkled on them. No harmful damage from this fungus, except perhaps a little shading of the areas affected. You can hose off the spores, brush them off with your shoe, or mow to remove them from the turf.


June—Early September

Gray Leaf Spot: Watch out for gray-brown, blotchy to diamond -shaped lesions on the grass blades (mostly on St. Augustine lawns). If you see this on your lawn, think back to if you just applied nitrogen to the turf through the summer, because you saw yellowed-leaves. You might have thought your turf needed more nitrogen, but in fact, the application of extra nitrogen could have increased likelihood of fungus. Systemic fungicides like Fertilome F-Stop, Bonide Infuse, Bayer Advanced Fungus Control, can help, but also refrain from applying nitrogen fertilizers from summer until cool fall temps.

Mid September—October (but we’ve seen it in spring!)

Brown Patch: look for 18-24 inch yellowing, irregular patches that quickly turn brown. These patches may merge into each other. Infected blades of grass will pull easily from runners, and you will see the left over, decayed leaf blade attached to runner. 

*To avoid the dreaded Brown Patch fungal disease, make sure you are not watering at night especially during these cooler months. Do not put your lawn to bed wet! 

*To treat the dreaded Brown Patch fungal disease after you already have it, you must treat it with a systemic lawn fungicide like: Fertilome F-Stop, Bonide Infuse, Bayer Advanced Fungus Control. If brown patch has been a recurring event in your turf, you might opt to treat as a preventative when conditions are favorable for disease and before disease symptoms are apparent.  (cooler weather, excessive rain/humidity).

*Horticultural cornmeal is an organic alternative preventative/treatment to fungicides, as well as is the peat moss mentioned above in the TARR section. The cornmeal must be “horticultural grade” not what you use to make Grandma’s cornbread. Also, don’t get it confused with “corn gluten” which is used as an organic weed pre-emergent.