March Garden Calendar

By John Chapman

March is a great month of gardening in general but we may still have some cold spells.
Diseases and Insects: With warm weather, expect to see more aphids on vegetables, shrubs, fruit and shade trees. A forceful spray of water will get rid of most of them, or spritz them with water with a few drops of dish soap added from a spray bottle which can be very effective especially it they are on your vegetable crops. For excessive infestations on your non-food plants and for Powdery Mildew you may want to treat with Orthenex as directed on the label. Spring winds bring spider mites - a forceful spray of water is effective or a miticide like Isotox. Little bitty bugs - almost microscopic - called thrips can attack your citrus blooms or rose blooms. Orthenex, Isotox or Malathion or the other pesticides are effective. Thrips, like bees, are pollinators, they are purely cosmetic with no major damage to your citrus however cosmetic is everything to roses. Thrips turn the edges of the petals brown, so treat with the insecticides I mentioned or ask your nurseryman.

Our feathered friends are also garden pests. Birds are also notorious for pulling up vegetable seedlings, in fact, any seedling. Cover with chicken wire. The new row covers of spun polyester are excellent for protecting young plants. The little baskets that fruits are packed in are excellent for protecting individual plants.

Flowers: Keep spent blooms from winter annuals picked off, and fertilized with a complete fertilizer, but one high in nitrogen and phosphorus. Do not remove foliage until it turns yellow.

Divide your established chrysanthemums. Discard the old crowns; replant young shoots, one foot apart. The soil should be well drained and enriched with composted manure, then add two pounds of ammonium phosphate (16-20-0) for each 100 square feet. Cannas may be divided most any time.

Vegetables: Early March is time to plant Beans (Lima & Snap), Beets, Carrots, Corn, Cucumbers, Jicama, Melons (Cantaloupe, Muskmelon, Watermelon), Okra, Green Onions, Peanuts, Pumpkins, Radishes, Squash (Summer & Winter), and Sunflowers. Plant transplants of Artichokes (Globe & Jerusalem), Egg Plant, and Peppers. Place shade cloth over tomatoes to keep leaf hoppers away. I love fresh garden green beans. I plant Blue Lake - bush. Terry Mikel of the county Co-operative Extension loves Contender. I keep them picked about every 10 days and watered so they will produce well into the summer. March is definitely tomato season. Good tomato selections Ace, Better Boy, Celebrity, Columbia, Champion, Early Pak 7, Early Girl, Heat Wave, Pearson, Yellow Pear and Cherry Sweet 100.Terry Mikel of the Cooperative extension likes Pearson Improved. My favorite is Roma because it is very meaty, mild and no core - it is great in salads.

For bell peppers, a vivid rainbow of colors is available from seed catalogs: With the original green we can have lavender-lilac, vivid-deep orange, bright yellow, deep red and chocolate brown. They not only taste good, they also add color to your garden and salads. Eggplant varieties to try are Ichiban, Black Prince and Dusky.

Clean up the herb garden by cutting back old and dead growth. Herbs to plant are mint, parsley, rosemary, sage and thyme.

This is also sweet potato slip starting time. Place the seed potatoes one layer deep side by side in a warm part of the yard or garden. Cover these with sand and then a layer of clear plastic. Keep well watered but not soggy wet. As shoots develop, raise the plastic cover. When the shoots are about six inches long, pull off the plants and plant them. One sweet potato will produce about 10 slips. I have used the ones out of the grocery store and they have done just fine - Irish as well as sweet potatoes.

Trees and shrubs: Now is good time to plant trees and shrubs. The earlier you get them in the ground, the more time the plants will have to get their roots established before the hot weather starts sucking the moisture out of the leaves. The soil should be excavated three to five times wider then the container but no deeper than the soil line in the container. I like to add phosphate, 0-45-0, and Ironite to native soil to help the roots get established quickly. Organic matter such as mulch is much better applied to the surface several inches deep to help keep the moisture in the root zone but six inches away from the trunk instead of mixing it with the back fill. Scuff up the root ball so the roots will start heading out instead of continuing to go around like they do in the container. I like to use nine 20-20-20-fertilizer briquettes in the planting hole of a five-gallon plant and 12 briquettes with a 15-gallon plant or tree. I put three briquettes directly underneath the root ball, add some back fill, add three more briquettes evenly placed around the ball, and add some more back fill and three more evenly placed but offset from the last three and so on. The fertilizer briquettes will gradually dissolve and now you won't have to fertilize for a year.

After planting, water the entire backfill zone. (Do not tamp down the backfill.) Subsequent water should then be applied close to the tree for about six months and then moved further outward each six months to accommodate spreading roots. This technique is based on the fact that trees have a shallow spreading root system with a few anchor roots rising from laterals. If planted this way, roots can more easily move outward in the loosened but unamended soil.

Time, also, for setting our container-grown roses. Feed them with one-half to one cup of a complete rose food. Water well and mulch with leaves, bark chips, peat moss or grass clippings. Re-stake and re-tie climbing roses. Repot container- grown plants and move them into open spaces. Evidence of freeze damage on trees and shrubs should be apparent now; prune back to live growth. While you're at it, shape the plant. This is also a good time to prune back hedges and shrubs that have become overgrown and dense. Hibiscus plants can be confusing. Limbs may lack a green color and yet produce new growth. At times, it may appear the plant is not worth saving; surprisingly, though, it bursts forth with new growth. The earlier you thin the fruit on your fruit trees to six inch spacing, after fruit set the sooner the remaining fruit will respond and the larger the remaining fruit will be.

Citrus: March and April are citrus planting months. Use great care in selecting your site: good sunlight but protection from scorching heat of late afternoon sun, particularly from walls. Young two to five year old trees transplant most successfully. Larger, older trees are more costly, harder to transplant without injury (to yourself and the tree), and suffer more from transplant shock. It will generally be three to five years, sometimes longer after transplant before fruit production and that is the same whether you plant a 2 year old tree or a 10 year old tree, so go small!

If you have grass growing up around the trunks you should put a plastic trunk guard to prevent mechanical damage (lawn mowers, weed whips, hoes etc.) All young trees should have sun protection to prevent bark burn as the weather warms up. I like to use Go Natural tree paint. It is a natural brown, blocks the UV rays and doesn't crack and peel with age. It is not necessary to pick all of your citrus. The fruits keep just fine on the trees until ready for use and leaving them on the tree will not harm them nor the new blooms. Water citrus trees every three to four weeks. Remember that watering deeply leaches salts in the soil down past the roots. Scratch up the soil around the plant considerably wider than the leaf spread. Increase the diameter of the irrigation berm as the plant grows. Keep grass out of this area; grass and citrus are not compatible because of their different water requirements. Besides the grass sucks up much of the fertilizer leaving little for the trees. I keep the grass killed under and around the fruit trees with Roundup, Kleenup, or Doomsday. They kill the grass down to the roots but won't harm the soil. If you accidentally spray something you don't want killed spray it off with water immediately or pick off the contaminated leaves. Do not fertilize the first year after planting, just give good deep watering. All transplanted citrus are first-year trees regardless of how old they were before you transplanted them. A two-year-old tree, and a five-year-old tree transplanted the same time last year are one-year-old trees. Thrip injury on new growth will be evident through late spring and summer, but it is cosmetic so it does not require control sprays.

Weeds: Winter weeds will set seed heads. Mow, hoe or handpick them before these plants have given you a batch of problems for next year. Prostrate spurge in desert landscapes and Bermuda grass can be controlled with pre-emergence herbicides such as Dacthal, Weed Stopper, or Surflan. An application in March and a second in early July will help control this pervasive weed. Use Wipe out, Weed Stopper, or Weed-Be-Gone if the weeds are already growing in your grass.

Lawns: Fertilize over seeded Bermuda once with 21-7-14. Water deeply, 8-10 inches every 3-5 days. When nighttime temperatures are above 60 degrees for at least 5 days in a row, mow progressively lower to three fourths inch to encourage spring transition back to Bermuda grass. Wait until April or May to plant grass seed. March is an ideal time to lay down Bermuda sod.

____________________________________________________________________

If you have a specific question for John please leave them on his voice mail 480-898-5636 or email him at john@johnchapman.com . Please leave your question, name, city, and phone number. For more of John Chapman’s gardening tips listen to news radio 620am KTAR Saturday morning 7:40-8AM. On Television watch John’s garden segments on Jan D’Atri’s Heart and Home on Sunday 12:30pm and replays Monday evenings 8 pm AZTV broadcast 27, Cable America 4, or Cox 13