Q: I just received some gerbera daisy plants. The older larger leaves on some of them have small blackish spots. You need to look closely to see them and they are more noticeable on the underside of the leaves. The tiny black spots or splotches seem to be almost running together. I cut off the leaves that are affected but the new leaves also are a little black on the tips of each ruffled edge. I think the store over-watered them. What can or should I do besides cutting off the affected leaves and watering them less? Is it good to replant them in well-draining soil since this soil seems very wet? Would it be too traumatic for me to repot them now? (E-mail reference)

A: There is no greater trauma than a plant slowly dying of some bacterial or fungal disease. It sounds like they were potted in either the wrong containers and/or soil. I would suggest replanting in new freely draining containers. Use fresh potting soil that has some good drainage characteristics. Gerbera daisy is an easy container plant to grow. Any problems that arise are usually the fault of either the container, potting soil mix, or the owner’s over-watering.

Q: This spring I purchased a dahlia in a pot. It looked very healthy and happy so I repotted and put it out with my other potted plants. It continued to grow and look very healthy, but it never grew any flowers. Do you have any idea why? Since it is still looking good I thought I would repot it and bring it indoors for the winter. Can this be done? (E-mail reference)

A: Dahlias will not bloom if they don't have enough light, which I am willing to bet is the problem in you case. If it is getting enough light, then you may have given it too much nitrogenous fertilizer. Another possibility is that your season is too short, and it should have been started earlier in the spring. March is what we recommend in North Dakota. There are several things that need to be done with dahlias: allow them to die back naturally in the fall either via light frost or from withholding water; cut the spent stems back to about three or four inches; gently lift the clump of tubers from their planting site and let them dry in the sun for at least a day; gently knock off the dry soil and store them for the winter. Repot the following March after dividing the tubers so that each one has an "eye" or bud.

Q: I've never really been a plant person, but, about two years ago, I received an approximately two-inch tall-crown of thorns. I've grown quite attached to it. It is now about a foot tall with one main branch and one smaller side branch. From pictures I've seen, the plant should have leaves along the stem, and should flower year-round. My plant only has leaves at the very top of its main stem, and at the top of its branch. It has never flowered. Is this normal? What can I do to get it to flower? Should I be feeding it anything in particular? (E-mail reference)

A: Basically, the crown of thorns can take as much direct winter sunlight as is available. Place it in a south window if possible, with a west window being the second choice. Allow the soil to dry between watering and only fertilize monthly when active growth is taking place during the spring and summer months. If it is going to flower, it will do so in the dead of winter. Repot every other year.

Q: My spring onions have gone to seed. I'd like to keep the seeds to plant next year but I'm not sure when to harvest the seeds. They currently look like big balls of dandelion. Could you tell me what they should look like when I’m ready to seed them? (E-mail reference)

A: If you are in the Northern part of the states, you should have harvested the seeds some time ago. Simply break the seed balls apart and plant the individual seeds that you find about one inch deep.

Q: I recently moved into a house that is surrounded by box elder trees. One of them, the oldest and largest, appears to have died suddenly. This happened in the spring of this year. This particular tree is very large, probably 60- to 70-feet tall. The person who lived here before me supposedly sprayed the tree for box elder bugs but I don't know what he used. Roundup was used on nearby box elder stumps to prevent suckers from sprouting. (E-mail reference)

A: The sudden death of a tree seldom occurs. When it does, it is often the result of a lightening strike. More often, the tree is in a state of decline that goes unnoticed by the homeowner, and when it is visibly dead, the cause was something either biological that has been going on for some time, or an abiotic event such as a water table change, construction damage, or spray drift from a potent herbicide. If you haven't done so already, get the tree removed ASAP. Large, dead box elders are not something you want to keep around as souvenirs. Unlike us, they don't get better with age. They usually have problems with internal rot, etc. One of many good reasons they are used in shelterbelt plantings and not around residences.

Q: If I use Miracle-Gro on my tomato plants, will it go into the tomatoes? My children will not eat them if I use it. Also, a lot of my tomatoes have big cracks in them. What is causing the cracks? (Jamestown, N.D.)

A: Miracle-Gro is a fertilizer compound of some 13 elements needed for plant growth. Those same elements are present in the soil and available to the tomato plants. Adding a broad-spectrum fertilizer like Miracle-Gro boosts the nutrient level of the soil and in many cases, makes up for other deficiencies. It has never poisoned anybody. The cracks on your tomatoes are caused by variable weather conditions. Some cultivars are more prone to developing them than others.

Q: I would like to know what to do with my two beautiful begonias this winter. Do they do well as house plants or can I leave them in the basement until spring? If so, how often should they be watered? I would also like to know what to do with about a dozen geraniums. I have them in planters outside, but have to bring them in soon. I am short on room so they have to go to sleep for the winter. Is it best to remove them from the planters and put them in brown bags until spring? (Summit, S.D.)

A: I am assuming the begonias you are talking about are the tuberous type. While they can be attractive houseplants over winter, the dry winter air is usually too much for them. I suggest, unless you want to put extra effort into their care, that you allow them to dry down and store the bulbs for the winter and repot them in March. With the geraniums, cut them back to about four inches, shake/knock off as much soil as possible and store them in bags or tied loosely with a string. Check monthly to see if they are withering. If they are, immerse in tepid water for about 20 - 30 minutes. Repot in February or early March.

Q: How long can I leave watermelons in the garage? They are South Dakota melons weighing between 30 and 40 pounds. (Jamestown, N.D.)

A: As long as the garage temperature does not drop below freezing, they should be okay for two to four more weeks.

Q: You were talking about wintering geraniums. I have three large pots that I bring inside, clip the dead flowers and they bloom all winter. I have a plant room with west and south windows and door. I’ve been doing it for three years. My spider plant also blooms all winter and my asparagus fern gets red beads on it. (Fargo, N.D.)

A: I know of many folks who have a set-up just like yours who are equally successful at keeping their geraniums going. For the rest of us, either dry storage or simply starting over next spring is the best bet. Congratulations on your very green thumb!