March Tips

It's time to get your garden growing

Spring is lurking in the wings, and it's the season for planting, pruning and helping nature pull off its annual rebound.

By

© St. Petersburg Times, published March 4, 2000

The threat of cold winter nights is now behind us. Those who have waited to prune can now get out their tools and begin the spring garden cleanup.

Once azaleas, poinsettias and camellias finish flowering they should be pruned. Pruning encourages new growth and produces a more compact, fuller plant. There is still time to prune excessive growth on crape myrtle and cut back to reduce their overall size. New growth begins in late spring. Flower clusters are produced on the new growth and pruning will encourage larger flower clusters.

Chrysanthemums make nice bedding plants, but become leggy if not properly pruned. Small flowered varieties should be pinched when they are 6 to 8 inches high. Unless these growing tips are pinched, plants may develop tall, weak stems that produce only a few flowers. After you pinch, new branches will develop along the stem. Pinch all shoots every two weeks until June 10 for early varieties, and July 1 for later varieties. Flowers will not form if you continue to pinch later than this.

Summer annuals can be started from seed directly in the garden or in seed flats. Marigold, impatiens, celosia and zinnia are easy to start from seed. Cover the seeds with a very fine layer of milled peat moss or sifted soil. Keep the area moist until the true leaves appear by misting the soil several times a day.

This is an excellent time to plant shrubs, trees, vines and perennials. Both hardy and tropical plants can be installed this month. When planting from a container or transplanting from another location, make sure you do not place the plant any deeper than it was originally growing. There are a few exceptions. Some palms can be planted deeper, but as a general rule it is best to plant at the same level or a bit higher to allow for settlement.

Wait about six weeks, then use the fertilizer formulated for that plant. Water every day the first week, every other day the second week, and twice weekly for the next four to six weeks, then once a week until the plant is established. Water should be adjusted for rainfall and soil types. Some plants may do better with less watering.

Select your caladium tubers as soon as they are available at the garden center. Plant them in a shaded area or one with partial sun. Space tubers 12 to 18 inches apart in a prepared bed of organic material. Cover the tops with about 2 inches of soil. Caladiums grow best in a moist, well-drained soil. Fertilize monthly during the growing season with 1 tablespoon of a fertilizer such as 5-10-10, 8-10-12 or 6-6-6 around each plant.

Caladiums may also be grown in containers indoors. Some cultivars that tolerate indoor conditions are Lord Derby, Fire Chief, Red Flash, Whorton, Porcile Anglais, Sea Gull, Beauty and Aaron.

Heavy pruning of hibiscus is best done in the early spring (February or March). New growth should produce flowers in five to six weeks. Light maintenance pruning may be done any time of year to keep plants at desired heights.

Cuttings taken during pruning can be used to propagate new plants; however, softwood or new-growth cuttings root more easily. Place them in a well-drained medium, such as equal parts of peat and coarse builders' sand. These cuttings should be 4 to 6 inches long and will usually root in about six weeks. New plants should begin to flower in about nine months.

Scale insects on camellia can be troublesome at this time of year. Tea scales are found on both upper and lower leaf surfaces. This armored scale secretes a waxy covering over its body, then lives and feeds under this covering. Dimethoate (Cygon) is a systemic insecticide absorbed by the plant and translocated throughout its tissues, making the plant toxic to scales. Dimethoate can be applied to the foliage or soil.

Malathion plus oil emulsion, acephate (Orthene), Diazinon and Ethion plus oil emulsion can also be used in scale control. Read the manufacturer's label carefully and follow all instructions and precautions.

Many bulbs can be grown successfully in Florida. Amaryllis, canna, crinum, daylily and spider lily are very common in our area. Some are true bulbs; others are rhizomes, tubers or corms, but we usually clump them all together as bulb plants.

You may wish to try some different ones this year. Amazon lily (Eucharis grandiflora) can be planted from February through May and will bloom in the winter. They need partial shade and should be planted with the tip of the bulb on the surface of the soil. Amazon lilies will grow in the ground, but in Florida they do best if grown in pots. This is because they bloom in the summer. For those who are really daring, choose the voodoo lily (Amorphophallus spp). The corm is planted 4 inches deep. Flowers are very showy but have a bad odor; the leaves are large and spectacular.

Christmas poinsettias can be removed from their containers and planted outdoors as soon as any danger of frost has passed. Dig your planting hole 12 inches wider and 6 inches deeper than the root ball. Back-fill the hole with a mixture of peat moss and the soil removed from the hole. Your poinsettia should fit in the hole at the same depth it was in the container.

Firm the soil to prevent settling, then place the plant in the hole and fill around the ball with your soil mixture. Water every other day the first week, then once or twice a week thereafter or as needed to keep the soil moist but not soggy. Poinsettias have a tendency to get root rot when too wet or in poorly drained soils.

Vegetable gardens should be in full swing this month. Remember to keep watch for insects and diseases and be prepared to treat at the first sign of invasion. Vegetables are annual plants and will use a lot of fertilizer while growing. Keep side-dressing with fertilizer every five to six weeks. There is still time to plant pole beans, lima beans, cantaloupes, collards, okra, sweet potatoes and summer spinach.

Papayas are not true trees but are large, herbaceous perennials with hollow stems that produce melonlike fruit most of the year. The main reason we call them trees is that under ideal growing conditions papaya plants may reach a height of 30 feet or more and produce fruit for several years. They're native to Central America and the West Indies but are now naturalized in many tropical areas.

Papaya plants are different from most other fruit crops. They can be either female, whose large blooms are produced near the trunk; male, which produce a cluster of flowers on a long stem; or bisexual, which have small male flowers on either side of the female bloom. You won't know until they flower which kind you have. It's important to know the flower type, because female trees need pollinating from a male or bisexual tree in order to produce fruit. Male trees seldom fruit, but occasionally a perfect flower will form on the male plant and a small fruit will develop on a long stem, but this fruit is not very desirable. Bisexual trees are self-fruitful, so that is why most nurseries generally sell the bisexual variety.

One question frequently asked by homeowners is: How can I tell when my fruit is ripe? It's easy to tell when papaya fruit are ripe because they turn yellow. You can let the fruit ripen on the tree, but birds or wild animals may get them before you do, so it's best to harvest when the lower half starts to turn yellow. It may take several days for the fruit to finish ripening on the counter top.

Papayas are not only low in calories but are high in vitamins A and C as well as potassium and fiber. They also help sooth an upset stomach. Papaya trees are susceptible to freeze damage and temperatures below 32 degrees F. may kill even large trees. So you may find yourself stuck with a lot of green fruit. Don't worry -- green fruit can actually be cooked and eaten as a vegetable, or sliced and laid on tough meat as a tenderizer. The seeds, which taste like watercress, are often crushed and put in salad dressing.

If you are interested in starting your own papaya seeds at home, follow these few simple steps. Get the kids involved. Since papaya plants produce fruit quickly, it's a good choice for a child's garden. You can buy a papaya fruit at the store, remove the seeds and wipe off the gelatinous covering with a paper towel, then plant several seeds in peat or potting soil. Place the pots in a bright, sunny area and keep the soil moist. The seeds should sprout in 10 to 15 days.

When the trees are about 8 inches tall, they can be planted in the garden. Mulch is very important, not only to help retain moisture but to recycle organics into the soil. In order to get good crop production, papayas need to be fertilized monthly. With proper care you can be harvesting fruit in about eight to 10 months.

Most citrus trees purchased for the home landscape are grown in containers and can be planted any time of year. The preferred time, however, is late winter or early spring. All grasses and weeds should be removed from an area 4 feet in diameter where the tree is to be planted.

Thoroughly spade the planting area to a depth of 2 to 3 feet. Remove the tree from the container and, if it is pot-bound (tightly woven roots), make several vertical cuts in the root ball to stimulate formation of new roots. Set the tree in the ground slightly (1/2 to 1 inch) higher than it was in the container.

Refill the hole around the plant with about one-third of the soil, then water to remove any air pockets. Allow the water to settle, fill the hole two-thirds full of soil and re-water. Finish filling the hole and firm the soil around the tree. Build a water basin around the tree at least 3 inches high and 30 inches in diameter. Water three times a week for two weeks, then drop off gradually to once every seven to 10 days during periods of little or no rain. The young citrus tree will need some attention if it is to thrive and be productive.

Watering is critical -- too much water can damage the roots, causing rot; too little water will cause wilting, very hard on the young tree. Citrus trees (especially young ones) should have about 1 inch of water every seven to 10 days. Do not fertilize a newly planted tree until new growth appears, then apply about 3/4 to 1 pound of a mixed fertilizer such as 4-8-8, or 6-6-6 with trace elements.

Always remove suckers below the bud or graft union on roses, gardenias, citrus, avocados, mangos or any grafted plant. These shoots will grow quickly and become dominant, often taking over the upper portion of the plant.

Heavy infestations of whitefly may suddenly appear on citrus leaves. Check the underside of leaves for the pupae, which look like clear scale insects. Spray with malathion, being sure to get under the leaves. Do not spray citrus trees when they are flowering. Gardenias and viburnum are other plants bothered by whitefly. Follow label directions for Malathion use.

Spider mites are a big problem on many plants during warm weather. Signs of mite infestation are chlorotic spots on leaves, rusty needles on junipers and stippling of leaves; when the infestation is heavy, you may be able to see webs. Miticides such as kelthane, or safer soap can be used on most plants. Read labels carefully.

Most Florida soils are low in magnesium. The symptoms of magnesium deficiency occur on older leaves because the nutrient is able to move from older growth to new growth. Magnesium deficiencies are common on many ornamental and food plants. The older leaves of the Canary Island Date palm will become prematurely yellow from this deficiency. Grapefruit leaves adjacent to the fruit may be the first to become chlorotic. Using magnesium sulfate will correct this problem.

Roses, gerbera daisies, crape myrtles and other plants may become infested with powdery mildew as soon as new leaves appear. The fungal disease causes the leaves to be disfigured and also damages the flowers. Spray the plants with an approved fungicide. Apply according to label directions.

Nutritional deficiencies of palms can be caused by many things: The age of the plant, soil type and environment all have a direct relationship on the nutrition of a palm. The vigor and activity of the root system, which is affected by soil, water and temperature conditions, play a major part in determining the uptake of nutrients from soil.

Palms are monocots and usually show signs of nutritional deficiency in the old or new leaves. Many deficiencies occur as a result of a damaged or inadequate root system, and applying nutrients to the soil may not correct the problem. In most cases, it is good to apply a foliar spray of the deficient nutrient and also make a soil application of granular fertilizer.

Manganese is one of the most frequently noticed deficiencies. The leaves will be yellow or brown with a frizzled look. Palms may die if manganese deficiencies are not corrected. Spray the foliage with a mixture of 1 tablespoon of manganese sulfate in a gallon of water. This should be applied once a month for three months. Measure the trunk of your palm and apply 1/2-pound of manganese sulfate for each inch of trunk diameter to the soil around the tree. Do not exceed 5 pounds in any one year.

Boron deficiencies rarely occur in palms with well-established root systems but may be prevalent in the spring after a cold winter. The symptoms of boron deficiencies are reduced leaf size and a brown, scorched leaf margin. Other deficiencies are magnesium, iron, nitrogen, phosphorous and potassium. Preventing is much easier than correcting deficiencies. It may take six to 12 months to see the results of foliar or granular application of nutrients after injury appears. A balanced fertilizer with all necessary trace elements should be applied three times a year.

-- Compiled by OPAL SCHALLMO and NANCY VOLMAR of the Pinellas County Cooperative Extension Service. If you have questions, call them at (727) 582-2100.

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