Marianne Binetti

Marianne Binetti: Water your thirsty rhodies and azaleas in dry August

Forget your lawn in August. Instead, concentrate on those thirsty rhododendrons and azaleas.

Late summer is when these spring blooming shrubs are deciding how many flowers they should produce next spring. If the soil is dry in August, you’ll have fewer rhododendron blooms in May. It is easy to hand-water the shallow roots of rhododendrons, azaleas and camellias this month and hand watering plants with a hose is a great excuse to wander outdoors and enjoy a summer evening. Provide your thirsty shrubs with at least one inch of water a week to keep them forming flower buds.

Here are a few reader questions with answers.

Q. My front lawn is turning brown but my back lawn is still green in places where the shade keeps it cool on hot summer days. I want to save money on my water bill — how often must I water my lawn to keep it from dying? R.T., Tacoma

A. Most lawns need one inch of water a week to stay green but during hot dry weather, the grass in Western Washington will naturally turn brown and go dormant. No worries as your brown lawn will green up again in the fall when the rain returns. To keep your water bill low and your lawn green all summer work on a grass-roots campaign.

Aerate the soil in the fall, add topsoil, and improve the soil below the roots by amending with organic-based topsoil that will hold moisture. In Tacoma you can use a product called TAGRO made from municipal bio solids to improve the water holding capacity of your soil. For more information, go online and check out

Q. I have a hanging basket of mixed flowers. The petunias and geraniums look fine but the blue lobelia is brown and looks almost dead. What could have killed the lobelia but not the other flowers? P.T., Maple Valley

A. Lobelia is a lovely plant but it’s also a lush with a drinking problem. This trailing annual loves cool, moist weather and throws a fit if the roots dry out even once.

New growth can occur if you keep your lobelia roots moist. Cut back up to half of the damaged lobelia plant and add some fertilizer when you water.

If you don’t want to wait for new growth and an encore performance of your thirsty lobelia you can get rid of the entire lobelia plant by cutting off the top of the plant at soil level. Then the more heat-tolerant petunias, zinnias and geraniums will take over your mixed basket. These colorful characters can control their drinking and still be the life of the summer patio parties.

Q. My tomato plant has yellow leaves. I do see small green tomatoes. Why are the leaves yellow? P.P., Renton

A. Foliage will turn yellow if a plant has too much water, too little water, lack of nitrogen, damage from pests like mites and various disease and weather conditions.

If the plant looks wilted or limp you can suspect root damage from poor drainage, dry soil or even a mole or vole. If the yellow leaves have brown tips, then too much fertilizer or sun may be the cause. Webbing on the foliage is a sign of spider mites turning the leaves yellow. Yellow leaves with green veins is often a sign that a plant is lacking in iron.

Feel the soil for moisture, check for mites, fertilize and hope for the best.