Tom MacCubbin: Tackle nematode issue before planting.
Question: I like growing tomatoes but have nematodes in my soil. What can I do to ensure healthy plants and a good crop?
Answer: Gardeners with nematodes in their soils know they cause major damage to the roots of most vegetables. While there are many types of nematodes, the ones that affect vegetables are microscopic round worms that cause the roots to swell. They are known as root knot nematodes, and they make the roots much less effective at supporting plant growth.
Start your nematode control program by looking for resistant tomato varieties. These plants tolerate some nematode activity but can still be affected. If you are ready to plant, open a hole several feet in diameter and about 8 inches deep and fill with potting soil. Then add the tomato transplant.
Gardeners can also grow tomatoes in large containers filled with potting soil and use soil solarization during the summer to help avoid these pests. Presently there are no reliable chemical controls for home gardens.
Q: My lawn is brown in spots and dries quickly during this hot weather. Should we apply fertilizer at this time?
A: Unless you can keep the turf moist, it is not going to utilize the fertilizer nutrients. With limited watering there is the possibility nutrients could concentrate and affect root systems. In general newer fertilizers won’t release their nutrients until there is adequate water. But to be safe, why not wait until you can water more or the rainy season returns to apply the next feeding?
Do keep in mind, the last feeding before fall has to occur by the end of May in most areas affected by fertilizing regulations. This means you may have to apply one of the modern slow-release fertilizers to the home lawn before the rainy season returns. When adequate water becomes available it activates the fertilizer.
Q: I purchased a bromeliad with a colorful flower that is now turning brown. What should I do for the plant?
A: What appears to be a bromeliad flower is usually an inflorescence composed of many blooms. Even after the real flowers fade, the stalk and leaf-like portions can continue to be colorful for weeks. When they do turn brown, the whole stalk can be cut back into the mother plant to make the bromeliad more attractive.
Often when the blooms start to deteriorate new shoots form at the base of the plant to create more bromeliads. They gradually become the new plant as the mother plant also deteriorates. You can let them fill in for the mother plant or divide the cluster to form new and separate bromeliads. Keep all moist and provide light feedings to encourage growth.
Q: We discovered our crotons were dying due to whiteflies. It was suggested we apply a horticultural oil spray. Is this the right treatment?
A: A good rule is to pick the least toxic product first to attempt control of plant pests. Horticultural oils have been available for a long time and are effective insecticides of low toxicity to gardeners and plants.
Obtaining good control with horticultural oils means following the label instructions and hitting the insects with the sprays. Some insects are likely to be missed and repeat sprays are often needed. Use of newer systemic insecticides is another option as they enter the plants to control the insects as they feed. Newer whitefly pests are becoming resistant to these products and horticultural oils may be one of a few sprays still giving control if systemic attempts become ineffective.
Q: A spathiphyllum in my home consistently has brown margins around the edges of the leaves. How can I keep the leaves totally green?
A: Plants can talk but we have to understand their message. Usually brown edges try to tell us there is not enough water to keep the foliage moist. This may be water in the soil or surrounding air. If you are keeping the soil moist this is likely a dry air problem. Possibly the simplest solution is to find the plant a new location.
During the hot, humid months you might select a site outdoors under a tree or on a shaded patio. Your spathiphyllum, also known as a peace lily, is not going to be happy indoors with air conditioning, which tends to keep the plants dry, too.
Q: My gardenia has produced lots of blooms that are turning brown. Should I remove the old flowers to encourage additional blooms and make the plant more vibrant?
A: Kind of ugly is what you might call gardenia blooms fading fast and covering bushes throughout much of Florida. Luckily the blossoms drop quickly so the brown look is rather short-lived. Most gardeners do nothing and ignore the faded blooms for a few days.
It’s doubtful that handpicking the declining flowers from the shrubs is going to do more than make you feel a bit better. Many varieties continue to share a few flowers with gardeners throughout the summer, but by now the major displays are nearly over. Use this time after flowering to reshape gardenia plants and, if needed, reduce their size. Most are also ready for a late spring feeding.