I have an heirloom (Brandywine) tomato plant that I purchased at Eisley's nursery here in Auburn. It is about 6 feet tall with lots of branches and leaves. It has gotten dozens of blossoms, but they dry up and fall off. I've not had one tomato off that plant!

I have an Early Girl next to it and I've been eating lots of good-size tomatoes from that plant.

What would cause this difference?

– Ruth Krasner, Auburn

According to UC Master Gardener Bill Pierce, it's not unusual for heirloom tomatoes to produce a poor crop. Tomatoes are self-fruitful, so a special pollenizer is not needed. It could be that for some reason the pollen in the Brandywine dried before fertilization took place.

Night temperatures below 55 degrees, day temperatures above 90 degrees or a lack of sufficient sun exposure can contribute to flower drop.

To ensure plenty of tomatoes, consider growing one or two hybrid varieties in addition to heirlooms.

I have two Ace tomatoes. They have been planted on the east side of the house and get about seven hours of sun each day. I have watered them each with one gallon of water every day and fertilized them twice.

Recently, the tomatoes started cracking at the stem end and very often the cracks become black. I have not eaten them.

I have no tomato worms, but what caused the cracks? Is it a soil problem, fungus or what? We live among the almond and walnut orchards. Should I do something different next year?

– Genevieve Lybrook, Chico

Cracks radiating out from the stem of tomatoes are caused by high temperatures and high sunlight, said UC Master Gardener Bill Pierce. Some varieties are more susceptible than others.

Keep soil evenly moist and maintain good leaf cover, so that the fruit is protected from hot summer afternoons. The black material in the cracks is mold and you are wise to discard these fruits. Many times the cracks are just cosmetic and the fruit is edible.

My orchid plant has finished flowering. My question: What do I do about the stem? Do I cut it off after the flowers have fallen off or do I leave it alone?

– Pam Zebrowski, Vacaville

Some orchids produce offshoots on their stems that can be removed and grown as new plants, according to UC Master Gardener Bill Pierce. Other varieties rebloom off old stems.

Since you did not mention what type of orchid you have, it would be best to leave the stem in place until it begins to shrivel and dry. Then you'll know you have not destroyed anything of value, such as a new baby plant.

Varieties that rebloom on old stems include the popular Phalaenopsis or moth orchids. In that case, cut the flower spike halfway down with a clean, sharp blade after the last flower falls. Seal the cut with melted candle wax to prevent bacterial infection. Feed and water your orchid as usual. A new shoot should appear in a few weeks and rebloom in three to four months.

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