Q: My citrus tree produced a 4-pound orange. How unusual is this? I don't do anything special to the tree; I just let it grow.

A: I worked with UCR's Citrus Variety Collection, which contains over a thousand different varieties, for many years and never saw a 2-pound orange let alone a 4-pound orange. If what you have is truly a 4-pound orange, it is one for the record books.

What I think is more likely is that your tree produced a rootstock sucker that fruited. At the nursery, citrus trees are budded or grafted onto more vigorous rootstock varieties, and some of these varieties can produce extremely large fruits.

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In the home garden, rootstocks occasionally produce their own branches or suckers, and if they are not removed, they compete with the scion and make fruit of their own.

In the home garden, these rootstocks occasionally produce their own branches or suckers, and if they are not removed, they compete with the scion (grafted variety) and make fruit of their own. This also happens, especially with young trees, when the desired variety is killed by cold weather and the rootstock, which is more vigorous and cold-tolerant, grows in its place.

Inspect your tree to determine if the growth that produced the giant orange is originating from above or below the bud union. The bud union is usually about six to twelve inches above the soil surface. Typically there is a change in bark color or texture between the scion and rootstock that marks the area. Anything growing from below the bud union is likely to produce abnormal and possibly bad-tasting fruit and should be pruned away.

Q: I'm planning my summer vegetable garden. Several of the tomato varieties I am considering have no nematode resistance. Do you think they will do well anyway?

A: Nematodes are microscopic worms that live in the soil, and they are a common problem in western soils. There are many species of nematodes; some are beneficial, but others are injurious to plants. Some species of nematodes can feed on above-ground plant parts, but those that damage the roots are the most obvious.

Many gardeners become aware of their existence when they pull up an ailing plant and observe the distorted roots that are the result of an attack by the root knot nematode. Nematodes use the root as a food source, and the damage they cause prevents the plant from taking up water and soil nutrients properly. In addition, the physical damage they inflict may allow other pathogens a point of entrance to attack the weakened roots.

Many of the older tomato varieties and a few of the newer ones lack nematode resistance and give poor performance in our soils. Fortunately, many tomato varieties have nematode resistance; just look for a capital N after the variety name as an indication of this trait. I would not consider growing a tomato variety that lacks nematode resistance.

Ottillia "Toots" Bier has been a master gardener since 1980.