University of Florida

Vegetable Gardening: Most Asked Questions

Vegetable gardening can be a fun and enriching experience, but it's not completely intuitive, especially if you're new to gardening (or new to Florida). Here are some questions we hear over and over again—with solutions and suggestions.

I’d like to try a garden, but have never grown vegetables in Florida. Can you recommend a good resource?

Yes, the Florida Vegetable Gardening Guide will provide lots of helpful information on how to start and maintain a garden, planting dates, and other useful advice.

My squash fruits get an inch or two long, then shrivel up and die. What's the problem?

This is a pollination problem. Squash and all plants in the cucurbit family (cucumber, melons, pumpkin, and squashes) have male and female flowers on the same plant and need bees to carry pollen from the male blooms to the female blooms. Only female flowers bear fruit. They can be identified by the small fruit found just behind the bloom. If pollinated, these tiny fruits begin to develop; if not it shrivels and dies. Bees will not be present if the garden is regularly dusted or sprayed with insecticides.  Hand pollination (http://edis.ifas.ufl.edu/HS398) of the female bloom can be done when bees are absent.

What causes the hard spots on the outside of my tomatoes?

This damage is caused by the green stinkbug (http://edis.ifas.ufl.edu/in534). This pest has a needle-like mouthpart which it inserts below the tomato skin to suck out sap. The empty cells create a hard, colorless spot. Stinkbugs cause the fruit to have poor aesthetic quality, but the fruit is still edible.

My tomato plants have lots of flowers, but they drop off without setting fruit. Is some bug eating the flowers?

Blossom drop can be caused by too low or too high night temperatures which interfere with pollination, too much nitrogen fertilizer, too much shade, over-watering or even insects, such as flower thrips. Choose varieties that are adapted to Florida's climate and soil. A list of some recommended varieties can be found in the Florida Vegetable Gardening Guide.

My seeds germinate and start growing, but then turn brown and collapse. What is the problem and how can I treat it?

Damping off is caused by several fungus diseases that live in the soil. Excessive moisture, planting seeds too deep, and/or planting too early in the spring when soils are too cool can contribute to this problem. Prevention is possible through soil solarization (http://edis.ifas.ufl.edu/IN824), plowing the soil prior to planting, planting disease-free seeds and/or transplants, and/or buying seeds treated with a fungicide. Practicing crop rotation and providing good drainage will also help this problem.

My okra and other vegetables were not growing well, and when I pulled them up the roots were covered with tumor-like growths.  What is this?

The galls and poor growth are the visible symptoms of root-knot nematodes. Nematodes feed on and damage roots which results in poor water and nutrient uptake by the plant. The best treatment for nematodes is soil sterilization by solarization (http://edis.ifas.ufl.edu/IN824).  This must be repeated at the start of all gardening seasons. More information on managing nematodes can be found in http://edis.ifas.ufl.edu/VH037. Knot-like growths on the roots of beans and other legumes are usually from beneficial nitrogen-fixing bacteria. 

I planted onions this year. The tops grew, but the plants never produced bulbs. Why?

Your onions may not have produced bulbs for several reasons:

  1. They were not bulbing onions; rather they were shallots, green, or multiplier types that do not form large bulbs.
  2. They were the wrong type of bulbing onion; in Florida "short-day" types are recommended. See the Florida Vegetable Gardening Guide for recommended varieties.
  3. They were planted too late. Bulbing onion seeds or transplants must be planted in the fall. They need a long growing period under short days to stimulate them to produce bulbs.

Garlic, like onion, is a long-season crop which is planted in the fall and harvested in the spring.

The bottoms of my tomatoes have dark brown, hard spots. Can I treat them with something that will correct this?

Blossom end rot is a nutritional disorder of tomatoes and peppers which is best prevented—not cured. It's caused by a deficiency of calcium which can be caused by a number of things:

  1. Calcium-deficient soil. Soil pH should be 6.0-6.8. A pH lower than 6.0 may not supply enough calcium, therefore, lime must be applied at a rate of 3-5 lbs./100 sq. ft. Soil used for vegetables should be tested for pH and calcium level. For more information, see Soil Testing on the UF/IFAS Extension web site.
  2. Poor watering practices. Dissolved calcium is carried into the plant in absorbed water. Irregular watering or dry periods may therefore contribute to blossom end rot.
  3. High nitrogen rates from too much chemical fertilizer or manure applications cause excessive growth of leaves and branches causing calcium to be re-directed to foliage instead of fruits.

If I plant different types of squash in my garden, will they cross-pollinate and produce inferior fruit?

 All plants in the cucurbit family (squash, melon, cucumber) will cross-pollinate, but the fruits will be true-to-type. However, the seeds from those fruits, if planted, would express the crossed-up genetics and are likely to be undesirable.

I planted vegetable seeds, but many of them did not come up. What happened to them?

Poor germination (or none) can be caused by several factors.

  1. Some insects such as mole crickets will eat seeds. When tunnels from these insects are seen, a pesticide bait, granule or liquid can be used for control.
  2. Seeds planted too deep may germinate but may not have enough food reserves to make it to the soil surface. A general rule of thumb is to never plant a seed deeper than twice its width.
  3. Too much water which rotted the seeds or aggravated soil-borne diseases which killed the seedlings.
  4. A dry period which can cause the developing seedlings to die.
  5. Seeds may be too old. Always use fresh seed. Check the viability date on your seed packets.

Can I grow asparagus in Florida?

Florida's warm and wet climate does not usually induce the long dormant period asparagus needs to produce spears.

For detailed information on asparagus and many other vegetables not commonly grown in Florida see Minor Vegetables.