Why Did Tomatoes Turn Brown and Die?
QUESTION: After 15 years of growing beautiful tomatoes, rotating crops each year, doing the same things, all of a sudden we have what the nurseryman calls “tomato blight” in the soil, which he says we will never get rid of. The plants get about two feet tall and start turning brown and die. Please help.
ANSWER: Remember how hot and dry it was last summer? True tomato “blight” is a fungal disease that requires high humidity and cool nights; it is not really a problem in the arid West.
But Fusarium wilt is and your problem featured its classic symptoms. This is a soil-borne fungal disease that generally does not cause serious problems unless soil and air temperatures are high for a prolonged period, just as we experienced last summer.
Unfortunately once it strikes your garden, it is more likely to attack again, and there is no known way to take the disease out of the soil.
But, tomato breeders have successfully developed Fusarium-resistant varieties so look for the letters “VF” or “VFN” after the varieties’ name. “Better Boy VFN” contains inbred resistance to three specific problems that commonly plague tomato growers.
The “V” stands for Verticillium wilt, which reduces harvests dramatically and weakens, but seldom kills, the plants.
The “F” stands for Fusarium wilt, which initially may resemble Verticillium wilt, but then usually kills the plants about the time they are big enough to flower.
(The “N” is for nematodes, which are tiny parasitic worms that stunt or kill the plants by creating swollen, knotty galls on the roots.)
Select a variety with at least the letter “F” after its name, and you should be back in the tomato business.
What’s the Secret to Pruning Pomegranates?
Q: Our pomegranate tree (which we have never pruned) has spread out like a giant fountain on the side of the house, and we can no longer get by it very well. We love the fruit and the syrup we make from it. Is there a way to prune it so we don’t lose too much fruit? Do we need to spray it with anything or cut out some of the fruit to make the rest bigger?
A: You’re in luck--pomegranates produce their fruit on new growth. They are the kind of plant that will produce good crops whether you prune them or not. You may cut back the bush as much as you want without any significant loss of flowers or fruit.
Spraying is not necessary since pomegranates normally have no pests or diseases that attack them, though they did have a tough time with the ash white fly a few years ago (which is now largely controlled by introduced predator wasps).
They don’t need thinning, so the only thing to consider is watering. Although pomegranates are pretty drought tolerant, the fruit will crack and split if the soil dries and then is watered. Keep the ground uniformly moist to reduce splitting fruits.
Can You Grow Peach Tree From a Cutting?
Q: A friend of mine has a peach tree that I like. If we cut off a branch and plant it in my yard, will it grow into a tree for me?
A: Unfortunately stone fruits (peaches, nectarines, plums, apricots, cherries) do not normally root from cuttings. Planting a branch from your friend’s tree will not work. These types of trees must be grafted onto the already-growing roots of a compatible variety.
In case you’d like to know, fig trees and grape vines do root easily from cuttings. Plant stems in late fall or early winter, preferably in sandy soil. They will usually sprout in the spring, and figs will often fruit that first year. But most other fruit trees require special techniques and skills for successful propagation.
