Question: After application of a granular weed and feed fertilizer with a herbicide in it, what is the chance that there is herbicide carryover into the clippings after a few rains? Can these clippings be composted for general use?
Answer: General recommendations are to wait about a month, or at least until the lawn has been mowed two or three times, before using the clippings. Generally, this is more critical if the grass clippings will be used immediately as mulch. Composting should provide ample opportunity for most commonly used herbicide residues to break down before the compost is used. Organic matter is generally composted for several months before use, so there is ample opportunity for the residues to break down.
Question: Do leftover fertilizers lose their effectiveness from one year to the next? How about pesticides such as herbicides, insecticides and fungicides?
Answer: Fertilizers retain their effectiveness indefinitely as long as they are kept dry. Always keep fertilizers well-sealed in their bag or container. Fertilizers can absorb humidity from the air and actually turn into slush if not sealed up properly. Even if this should happen, the fertilizer can be used, it’s just more difficult. If granular fertilizers get damp and dry out, they can form hard clumps. These may be broken apart with a hammer and fertilizer used per label directions.
Ideally, pesticides, especially liquid formulations, should be used up the first year after purchasing them since they will lose potency over time. For that reason, I always recommend gardeners buy the smallest container of a pesticide that is available. Most of us have far too many partially used bottles of pesticides hanging around. You might also choose to purchase pre-mixed, ready-to-spray pesticides, when available, since you will use them up faster. Always keep fertilizers and pesticides stored safely. If you have young children, that means under lock and key.
Question: Some of my tomato blossoms are being chewed off by some insect. What can I do to stop this?
Answer: Fortunately, there aren’t any insects — or any other critters — that cut the flowers from tomatoes. The flowers are simply aborting and dropping off without setting fruit. This is common with the first cluster or two of flowers a young tomato plant produces after planting. Flower drop also occurs this time of the year because most tomato bushes have set their main crop of fruit at this point. A tomato plant with lots of tomatoes already set will often drop flowers. The main issue now, however, is heat. The month of June is accompanied by high temperatures. When nighttime temperatures stay in the mid-seventies and daytime temperatures are in the 90s, tomato flowers generally fail to be pollinated. (NOTE: The expectantly cool temperatures that occurred on Monday morning with the last rainfall will not negate flower drop on tomato plants.)
Tomato flowers are self-pollinating and do not require insects. As summer temperatures become warmer, the pollen becomes less viable and not able to pollinate the flowers, especially in standard size tomato varieties. The Master Gardeners expect to make their last harvest of standard size tomatoes over the coming week. In contrast, many of the smaller size cherry tomatoes will continue producing tomatoes for several more weeks.
That’s why we plant tomato transplants from mid-February to mid-March in our growing area. Planting later means much of the flowering will take place once it gets too hot, and a poor crop will result.
Rainwater Harvesting Seminar
Harvesting rainwater is an old idea that is gaining popularity in Texas, where our growing population and frequent dry spells make it important to use our water resources efficiently.
Maybe you’ve heard something about rainwater harvesting and you’re intrigued. Or maybe you’re nearing a decision to invest in a rainwater harvesting system. What do you need to know before you start? Where can you go for more information? What questions do you need to answer before harvesting rainwater?
Don’t let that water go down the drain! Learn to collect and store rainwater. Nat Gruesen, Galveston County Master Gardener and Certified Rainwater Harvesting Specialist, will provide a presentation on Rainwater Harvesting where he will discuss practices and ways to incorporate rainwater collection into your residential landscaping along with methods for making your rainwater barrel.
This seminar will be conducted from 9-11 a.m. Saturday at the Galveston County AgriLife Extension Office located in Carbide Park (4102-B Main Street) in La Marque. Pre-registration is required to ensure availability of handout materials (e-mail email@example.com or phone 281-309-5065) to pre-register.