- The bottom of my tomatoes has dark brown, rotten spots. What is this and how can I prevent this problem?
This is a nutritional disorder called blossom end rot. This deficiency may result from:
Soils being deficient in available calcium. Soil pH should be 6.0-6.8. A pH lower than 6.0 may not supply enough available calcium, therefore, lime must be applied at a rate of 3-5 lbs. /100 sq. ft.
Infrequent watering will cause calcium to go out of solution, therefore, it is in a form which plants can not use. Soil must be consistently moist to keep calcium in solution and available to plants.
- When I plant onions, all I get are green onions. They never bulb?
There are two reasons why onions do not bulb: 1. Starting with onion sets will only produce green onions. You must start with seeds or seedling plants. 2. Planting too late in the season prevents bulbing. The seeds must be planted in the fall and harvested in the spring. Onion tops need exposure to the change in day length to stimulate the bulbing process. Garlic, like onions, is a long season crop. The seeds must be planted in the fall and harvested in the spring.
- Why do my tomato plants consistently drop their blooms?
This is a problem associated with several factors:
Variety selection is of utmost importance for all crops, including tomatoes. Varieties other than those that are recommended for this area by the University of Florida will not be adapted to the climate or soil conditions. Poor growth, bloom drop, and poor fruit set are to be expected from varieties not recommended for this area.
High nitrogen will cause a lack of blooms or bloom drop. High nitrogen availability will cause plants to grow excessive and lush foliage at the expense of bloom and fruit set. Reduce the nitrogen applied to the crop.
Tomatoes have a very narrow optimum temperature range which is best for bloom set and for production. Nights which are too cool or too hot will cause the bloom to drop. Planting tomatoes or any crop out of season is a common error and puts the plant under environmental stress resulting in poor growth and flowering. Late spring or early fall planting subjects tomatoes to temperatures that are too high for bloom set.
A water cycle which subjects the tomato plant to a wet then dry condition as opposed to a consistent moist condition results in bloom drop. This problem is very common in container grown vegetables.
Tomatoes require at least 6 hours of full sun. If tomatoes get less than 6 hours of full sun, poor blooming or bloom drop can occur.
- What causes the hard white or colorless spots on the outside of my tomatoes?
This is damage done by stinkbugs. These pests insert their mouth parts below the tomato skin and suck out the tomato sap. These empty cells create a hard, colorless spot. Stinkbugs do cause the fruit to have poor aesthetic quality, but the fruit is still edible.
- When planning a landscape, what security problems should be considered?
Keep your front door in view from the street. Let windows be visible. You may want to plant barberry shrubs beneath windows. The thorns can keep people away. Don't plant an area that can be a hiding place for burglars. Also, incorporate low-voltage lighting in your landscape design.
- How often should I inspect my plants?
A good rule of thumb is to inspect weekly. Catching a problem early makes it much easier to treat. Check both the top and bottom of the leaves, and check the soil surrounding the plant.
- If I don't cut off the dead blossoms on my flowers, will the plants die?
No, but you'll have less flowers than the plant would normally produce.
- What do I do for my houseplants while we're on vacation?
Depending on the type of plants. My first thought is to put them outside in an area with filtered light or partial shade. Nature does wonders for plants. Some people put them in the kitchen sink on a towel that is soaked in water.
- What is causing the buds on my hibiscus to drop off without opening?
There are a number of things that could be the culprit, such as thrips, caterpillars or nematodes. It could be a deficiency or overabundance of nutrients, or it could be caused by poor drainage, too much water or too little water. Examine your plant and the area for any of the above. If none of the above exists, be comforted in that it is the hibiscus' nature to prematurely drop buds, especially the doubles. Some varieties will do well for only a portion of the year. During excessively hot and dry weather, bud drop is often caused because the plant is not able to absorb the water it needs to compensate for the water lost through transpiration.
- What is dormant oil and when should I apply it?
It's a miscible oil, a safe, easy to use, and very effective insecticide that no bug can develop an immunity to. Its mode of action is very simple. As you spray your plant, preferably from the top down, it coats the twigs and branches, running into little crevices in the bark, quietly smothering any over wintering insect eggs. The eggs cannot get air, they do not hatch and viola! You have just eliminated preexisting problems.
- I have fairly large mounds that run like a snake. Are they moles?
It sounds like moles, and they're most likely feeding on grubs and insects in your lawn. If you get rid of the insects, the moles will leave.
- What insects are best controlled by systemic insecticide?
Small-sucking insects such as aphids, whiteflies, scale, mealybugs, spider mites and lacebugs.