QUESTION: We are getting a lot of conflicting information on whether we should be removing suckers on our corn and tomato plants. Is it necessary?
ANSWER: For years it has been a common belief that suckers robbed nutrients and water from the main corn plant, resulting in decreased yields
In reality, suckers are simply auxiliary corn plants that develop from one or more corn stalk joints at the base of the main stalk. They become nearly independent as they develop, partly due to the fact they will eventually develop their own root system. Suckers may compete somewhat with the main stalks, but given their late developmental start, they usually lose out in the competition for water, nutrients and light. Leave them on the plant!
With tomatoes, there's no hard and fast rule about leaving or taking off suckers. Many of the most popular tomato plants grown today are what is referred to as determinate or upright bush types that need very little staking, pruning or sucker removal. If you grow some of the older indeterminate varieties like Early Girl however, you may want to pinch out some of the suckers which originate between the main stem and main branch. Removing all of the suckers could potentially result in sunburn to the fruit so leave a few!
Sucker growth on fruit trees is commonly referred to as "water sprouts." With the exception of spur varieties, this vertical growth doesn't produce fruit and is not needed for tree growth. Moreover, in the tree canopy, sucker growth shades fruit bearing branches resulting in reduced yields and fruit quality. Now is an excellent time to eliminate sucker growth on fruit trees. The soft, succulent growth can be easily removed by hand. Removing them now saves pruning off hardened suckers next January.
QUESTION: Now that the warm weather has arrived our apple trees are losing leaves. We have been watering it on a regular basis, but the leaves continue to fall. What's going on?
ANSWER: I suspect your apple tree is infected with a fungus disease which is commonly referred to as "apple scab." This disease is easily recognized by the olive-green, or brownish black velvety spots of various sizes which develop on both surfaces of the leaves. The spots most often are round. Many times they have a fringe of radiating lines of fungus growth. Spotted leaf tissue often is raised or otherwise distorted. Infected areas may be irregularly shaped and cover most all of the leaf. Affected leaf tissue becomes yellowish and then brown. Serious leaf drop can occur by mid-summer, thus wakening the tree.
The key to successfully controlling scab is to apply fungicides early and thoroughly to protect new growth. WSU plant pathologists recommend applying the fungicide Captan according to labeled directions for the prevention of apple scab. Spray applications now will help to prevent infection of the scab fungus on newly formed leaves and fruit.
Mature apple fruit are much less susceptible to apple scab than immature fruit. However, infections can occur near harvest, which will not develop until apples are in storage. It can take as little as six hours of wetness at 70 degrees F. for an infection of fruit around bloom time, but it takes almost 48 hours of wetness at the same temperature to infect mature fruit.
QUESTION: We recently saw an advertisement in a garden magazine for a product that will automatically remove thatch accumulations in lawns. Does it really work?
ANSWER: "Wonder Amendments" such as bacteria, yeasts, enzymes and other "miracle cures" have no significant on thatch accumulation. Natural decomposition will occur from the organisms that are already in your soil when the lawn area is well drained and the soil pH is neutral (between 6 and 7). If your soil is acidic, periodically apply lime to bring it up to neutral.
A thatch layer of 0.5 to 0.75 inch is generally acceptable in home lawns, but anything greater can begin to cause problems and should be mechanically removed.
EDITOR'S NOTE: For answers to local gardening questions, contact Master Gardener Rachel Gana at 642-8723 or e-mail her at: email@example.com. Donald D. Tapio is a Southwest Washington area extension agent for Washington State University. He can be reached at 360-482-2934.