March Gardening By the Month

“There is no life I know to compare with pure imagaination. Living there, you’ll be free, if you truly wish to be.”- Willy Wonka


(Beautiful, blooming geraniums bring happiness to any patio!)


bonsais and lettuce011st WEEK:

The first of March is typically the last frost date, but we have gotten nipped as late as the first week of April.-SB

Harvest spinach, leaf lettuce, collars and other greens one leaf at a time as you need them for salads.

Don’t forget you can plant vegetables and herbs in containers if you don’t have space for a full garden.

It’s easy to find blooming plants in springtime, but budget for a few perennials that also bloom in summer and fall so you escape the “sea of green” that happens after your spring blooms end. -RSR

The first few days of this month is the last call for planting bare-root dormant rose bushes. They can be planted later with success, but they will not grow off as quickly or as well.-AJW

Divide summer and fall blooming perennials, including cannas, mallows, fall asters, mums and perennial salvias.

Prune the tallest, thinnest canes of nandina to 2″ to encourage thicker bushes.-TAE

Complete all transplanting of trees and shrubs.  Water well until roots have had time to establish.-LR

Last chance to apply pre-emergent herbicides and receive their full benefit.  Remember to water them in lightly.

Check irrigation systems for broken or misaligned sprinkler heads, correct water pressure, and proper coverage. This will save you water and money during our hot growing season. Consider purchasing a rain switch that will automatically turn off system when rainfalls have been adequate. -RSR

It’s too early to fertilize lawns.  Instead, aerate with a core-extracting aerator and top-dress with 1/2 inch of compost or compost-sand mix to revitalize grass.-EO  Wait to fertilize later in the month after your second mowing of the season.

If you haven’t already, mow your lawn to remove browned winter stubble.

Still time to mow/cut well established Asian Jasmine, liriope and mondograss, feed with a slow-release lawn food (never use a weed & feed).

Rather than pruning pear trees, use spacers to spread branches at a 60 degree angle.  Pruning pear trees heavily stimulates vegetation rather than fruit. Tree cut wounds also put them at risk for fireblight.

Fertilize fruit trees with 1 cup of slow-release lawn fertilizer per inch of trunk diameter. Spread it around the drip line.-CF

Hold off on spraying pesticides on blooming fruit trees if you can. Bees are busy pollinating and you will risk killing them and leaving yourself with little or no fruit.

Fertilize pecans with 21-0-0 or other high-nitrogen fertilizer on 30-day intervals early March through early May.-NS



salvia-gregii-12nd WEEK:

Geraniums, dianthus and petunias are good color plants for the sun during this transition from cool weather to hot. Salvia plants can be set out too.-EO

Feed deciduous trees and shrubs as they resume growth. The live oak leaves may be falling, this is normal, no cause for alarm.  The round growths on the leaves are wasp galls, harmless to the tree.  Use them for mulch.

Paint all wounds on oak trees with pruning paint or latex paint immediately after the wound is made or discovered in order to prevent the spread of oak wilt.

It is not too late to apply dormant oil to pecans trees that had PHYLLOXERA last year.

Watch for SOPHORA CATERPILLARS on Texas mountain laurel.  Use Bacillus thuringiensis (Bt) or malathion to control them.

Cut off any fruits set on Daffodils, Irises and other bulbs (and fertilize if not already done so).

The current crop of weeds in your lawn will die with warm weather. Keep them mowed to prevent reseeding. Mowing your lawn now will reduce weeds from reseeding and encourage turf grass to grow and green up sooner.-TAE

Ball Moss does not harm oak trees, but you can apply copper hydroxide (Cupro ) now to control it.

Mix 1-2 inches of compost into soil to prepare for veggie planting. -RSR

Side-dress onions with 1 cup of slow-release lawn fertilizer or 2 cups of organic fertilizer per 10 feet of row.-CF

Sow sweet corn, snap and lima beans and cucumber seeds.  Plant watermelons, squash, seed potatoes, carrots and all types of beans. Avoid planting seeds too thickly, think about final spacing and add just a few extra for insurance. -RSR

Finish pruning evergreen shrubs.  Wait on spring-flowering shrubs.

Apply slow-release fertilizers to landscape plants (not lawns) to gear up for the growing season.-EO


peppers1 facebook3rd Week

We have passed the average last frost date for San Antonio. It can still freeze! (The time of the latest freeze is still two weeks away.)  Spring is an exciting time for backyard bird watching as some of our familiar friends migrate home and join those who stayed all winter.

Plant warm-season annuals and vegetables such as tomatoes, peppers, petunias and Dahlberg daisies, but protect the plants if frost (or hail storm) is predicted.

Wait to fertilize your lawn until you have mowed real grass twice.  Fertilizing too early only benefits the weeds.

Weather is probably warm enough now to lay sod. Remove weeds, fill in low spots and rake soil smooth for good sod-to-soil contact. -RSR

Aphids are feasting on cole crops and other plants (and my roses). Try to wash them off with a blast of soapy water until the predator insects get them in control, or you can spray with Spinosad or Pyrethrin, or release ladybugs to chomp them away (no pesticides can be used when ladybugs are dwelling).  Oust aphids!-ROGB

Bare-root rose planting season is over, but you can  plant container-grown roses anytime. -RS

Revitalize leggy salvia, pomegranate, vitex, ceniza and other shrubs by removing the old stem at ground level.  Leave three to eight young stems. Clean up all perennial beds that have last seasons growth.

Begonias can be set out in the landscape.   Any begonia set out early will thrive in the sun.

Pansies, stocks, calendulas and other cool-weather blooms decline quickly if they dry out. Keep them well-watered.

Let potting medium of geraniums dry between waterings.

Prune crape myrtles in mid to late March for shaping. Do not cut their tops off.

Replenish the mulch of young trees. Place it in a donut shape so the mulch is over the roots but not against the trunk(at least 3 inches away).-CF

Sow bush lima beans, pole lima beans, cantaloupe and watermelon seeds.-EO

If weather is looking good, this is a good time for planting cantaloupes, watermelons and cucumbers.-TAE

Apply broadleaf weed killer to eliminate CLOVER, DANDELIONS, HENBIT and other weeds from turf.

Remove freeze-damaged vegetables from your garden to prevent disease.-LR


geraniums4th Week:

Consider geraniums for a splash of color on the patio or balcony.  They can handle full sun until temperatures increase.  Then move them to a location with less sun.

Cold-sensitive plants can be placed on the patio now (check weather forecast).  Be prepared to protect them if a late freeze threatens.

Fertilize new annuals and new perennials with a soluble fertilizer for the first 4-6 weeks as they establish their roots.

It’s not too late to prune crape myrtles.  Do not top the trees but, remove dead wood and excess stems (leave 3 to 6 per cane).  Cut back limbs, but try not to leave stubby branches.

Thin peaches and plums to one fruit every 6 inches when they reach dime size.

The first set of potted tomatoes can be placed in the garden now.  Place N-sulate on the cages for protection from wind and cool nights.

Hold off on mulching new veggie transplants. Allow the sun to continue to warm up the soil for a while.

Add more mulch around hardy perennials, shrubs, and trees if it is now less than four inches deep.  Keep mulch away from base of tree trunk.

Peak wildflower time in the San Antonio area probably will be during the first week of April.-CF

Begin a fruit-tree spray program, alternating fungicide and insecticide, after fruit blossoms fall.-EO

Ground temperature is warming up, and hot-season crops can be sown.  Consider planting Southern peas, pumpkins, peanuts, squash and okra.-TAE

Keep and eye out for cabbage loopers and aphids on cool-season veggies, BT contols caterpillars, and a spray of insecticidal soap can control aphids. But beware of spraying plants that are larval food sources for butterflies, or you will be killing them too.

Clean and oil pruning tools after you’ve finished all your pruning this month.-RSR


*  In updating this collections of useful tips, we have come across several comments, instructions and chemicals that are being replaced with newer techniques and materials. The tips have been updated accordingly.

Please note, most of the information shared here was obtained from Research-based sources (see contributors acknowledgements below), and from individuals who are considered very knowledgeable on a particular subject.

Many thanks to my contributors for sharing their wisdom so I can learn and share it with you.

PMA – Purple Martin Association; visit their web site @

SB – Steve Brown, meteorologist with KSAT; visit their web site @

CF – Calvin Finch, (former) Bexar Co. extension agent for horticulture, Texas Agricultural Extension Service (courtesy S.A. Express-News)

EO – Edna Ortiz, (former) Bexar Co. extension agent for horticulture, Texas Agricultural Extension Service (courtesy S.A. Express-News)

AJW – A.J. “Pop” Warner, Consulting Rosarian, writer of the book “A Year in the Rose

TAE – Texas Agricultural Extension Service, Bexar County (courtesy S.A. Express-News)

LR – Lynn Rawe, (former) Bexar Co. extension agent for horticulture, Texas Cooperative Extension Service (courtesy S.A. Express-News); visit their web site @

HG – John Howard Garrett, aka the “Dirt Doctor”; visit his web site @

NS – Neil Sperry, Texas horticulturalists, Publisher “Neil Sperry’s GARDENS” and contributor to S.A. Express-News.  Visit his web site @

ROGB – Rodale Organic Gardening Books

WBC – Wild Bird Center

JB – Jerry Baker, America’s Master Gardener, aka “The Yardener”.

RAG – Rene A. Guzman, (information compiled) courtesy S.A. Express-News

TGS- Texas Gardener Seeds. E-newsletter from Texas Gardener Magazine; visit their web- site @ www.

RSR-Month-By-Month Gardening Texas-Robert “Skip”Richter