Q I would like to plant some citron, but none of my seed catalogs lists it. Do you know where I might find some? Two fruits are used for citron. Citrus medica has 6- to 10-inch oblong, lemon-yellow, rough, thick-skinned fruit borne on a small tree or shrub with short spines. The fruit is fragrant. Unlike other citrus, the pulp is very scant.
The citron melon is a variety of watermelon (Citrullus vulgaris, variety citroides). It has hard, white flesh, with little resemblance to true watermelon. It must be cooked before it can be made into preserves or candied fruit.
We assume it is citron melon that you want. Seeds are available from Nichols Garden Nursery, 1190 North Pacific Highway, Albany, Ore. 97321.
Q Even though our iris bed is in full sun and good soil, it hasn't bloomed well for several years. Each spring the leaves appear to have some kind of brown spotting, especially along the edges. I have sprayed with Zineb, but the infestation does not seem to disappear completely.
Iris beds bloom best if they are divided regularly, about every three years, and if they are kept free of debris (which encourages borers). Also, the rhizomes should be above the soil in a sunny location.
You may have leaf spot, which the Zineb is probably controlling. Most likely, yours have borers, and they probably need dividing.
Eggs are laid on the bases of stalks and in debris in the fall. In spring, young larvae crawl up the leaves and enter, making pinpoint holes, later causing ragged leaf edges as they eat their way down inside.
Most areas become water-soaked looking and brownish. As they get to the rhizomes, the borers grow fatter and eat their way inside, often causing rot and complete destruction.
Control: Watch for holes and squeeze, running your thumb and forefinger up and down the leaf. Lift iris after bloom and cut out grubs and any rotted portion. Then dust with Benlate. Sprinkle a handful of bonemeal around each clump just before and soon after bloom.
Q I've just moved to New England and have space for a garden. I would like to grow vegetables and some small fruit. Being a novice, I don't even know where to look for information. Should I go to the public library?
The public library would have many garden books, while your county Cooperative Extension Service would have specific information for your area. They are a link between residents and the state agricultural college and would be able to give you a list of bulletins available on a large number of garden topics. Also, they may be offering courses in gardening.
You might also contact arboretums and garden centers in your locale for services and courses they offer. Ask for a list of area nurseries and seed catalogs; both are valuable sources of information.
For a national list, write: Avant Gardener, PO Box 489, New York, N.Y. 10028. There is a $2 charge, but it is probably the most up-to-date listing of garden products available and includes more than 400 mail-order horticultural businesses.
If you have a question about your garden, inside or out, send it to the Garden Page, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115. Doc and Katy Abraham are nationally known horticulturists, authors of several books on gardening, and greenhouse operators for more than 25 years.