Tomatoes sensitive to nighttime temperatures

Here are some questions I encountered this past week.

Q: Why are my tomato blossoms dropping?

A: A tomato is a warm season vegetable and very sensitive to cold weather, which causes blossom drop. Nighttime temperatures must be above 60 degrees for them to stick on, and we are just arriving at this temperature. Expect to see little tomatoes setting on, and they will continue until night temperatures rise above 70 degrees.

Q: Why are the bottom leaves of my tomatoes turning yellow?

A: It's a good indication your plants need more nitrogen. This element moves within the plant from the older to the younger growth, so add more nitrogen. Or you could be overwatering them. All plants prefer deep irrigations, so water less often but for a longer period of time.

Q: How can I strengthen a Bermuda lawn?

A: Bermuda lawns are prone to build thatch, or dead leaves and plant parts below the top growth. It becomes thick and when it dries out, repels water, resulting in an unthrifty lawn. To find out if you have thatch trouble, take a 1-inch-wide plug out of the lawn. Examine the area between the soil and green growth; if the dead area is more than a half-inch thick, dethatch. Rent a dethatcher to remove it. If this is your first time to dethatch, don't be alarmed with the damaged lawn; it will come back to a beautiful emerald green.

After dethatching, aerate the lawn. An aerator removes half-inch-wide plugs from your lawn about 4 inches deep so water penetrates deeper, making wiser use of your water.

Q: We want a small tree to fit between our condominiums. What would work?

A: Consider yellow bird of paradise (Caesalpinia mexicana) and Texas olive (Cordia boissieri). Both get about 10 feet tall. The bird of paradise comes with yellow flowers, and the olive decorates itself with crisp white flowers and also makes a great shrub.

Q: We just planted an olive tree and the leaves suddenly dropped. When I dig under the bark it seems OK but the leaves are all gone. What happened?

A: Upon quizzing this person, the tree was planted 6 inches too deep, with 6 inches of soil over the rootball. It was watered with lawn sprinklers. In this case, the rootball became bone dry. Remove the topsoil from around the tree so the roots can get air. Next, give the rootball an extended soaking, and do it weekly to get things going again.

Q: Should you plant vegetable rows in an east-west direction or north and south?

A: This is a mixed bag. Some seed catalogs recommend east-west row orientation to minimize shade from adjacent plants, but others recommend north-south orientation for the same reason.

In our valley, the sun becomes so intense that many plants need protection from it, so you might want to consider providing supplemental shade. Translated, directional orientation is not a serious concern. Watermelons, cantaloupe, squash, etc., need five to eight hours of early morning sun, because that is when bees pollinate best.

Q: What is a safe solution to get rid of aphids on my plants?

A: Knock them off with a strong jet of water, or use insecticidal soap. You'll find aphids close to blooms and new leaves on many plants this time of year.

Q: What is the white, fuzzy stuff at the base of my apple tree next to the trunk?

A: They are woolly apple aphids. Spray them with neem, but add a squirt of dish detergent to the spray to break down the fuzzy stuff so neem can reach the insect.

USING HERBS IN YOUR MEALS

Herbs add a savory touch to your meals. Learn firsthand how you can put some gusto into your dishes. This much-requested class will be at 8:30 a.m. Saturday at the Springs Preserve, 333 S. Valley View Blvd. For more information and to reserve your seat, call 822-7786.

Linn Mills writes a garden column each Sunday. You can reach him at linn.mills@springspreserve.org or call him at 822-7754.