Asparagus tops must be removed to discourage growth of beetles

An Orono gardener asks what to do with the tops of his asparagus plants now that they have been killed by the frost. He wonders if it is OK to just let the snow beat them down and allow the microbes to do the rest.

Of all the garden vegetables that are commonly grown, asparagus is perhaps the one crop that deserves more careful handling after the growing season. The reason is that asparagus beetles overwinter in the stems and their larvae eventually find their way into the soil where they damage the emerging spears in early spring.

So, by all means, remove the tops, burn them, shred and compost them or send them to the dump. It is wise to do this as soon as they have been stopped by the frost.

The same gardener had his carrot tops cropped by the local deer herd. Now he wonders if he should remove what is left of the tops before storing the carrot roots.

The answer is yes. Carrots have no need of any top growth when they go into storage. But don’t be overzealous and cut into the root itself as this merely opens up an avenue of unwanted bacteria and fungi to infect the root.

I have tried all sorts of tricks for storing the roots, including packing them in moist sand, sawdust and sphagnum moss. My cellar is just not cool enough to hold carrots in this way, so I have resorted to packing an old refrigerator full of carrots and winter cabbage, bagged in plastic. Energy efficient it may not be, but at least I get to eat the whole crop.

A Belfast gardener has been puzzled by erratic flowering and fruiting in his mountain ash trees over the years. He has tried fertilizing with Miracle Gro and found that it did nothing to improve the crop in the current year.

Mountain ash belongs to the rose family along with more familiar trees such as apple, crabapple and pear. Anyone who has old apple trees on his or property knows that they have a tendency to bear biennially, i.e. produce a heavy crop one year and little or no fruit the next.

To combat this tendency, apple growers prune their trees every year, usually in late winter or early spring. This stimulates the trees to be more reproductively active than normal. Also, orchardists apply a hefty amount of fertilizer under each tree at the start of the growing season which encourages better all-around performance.

Now, it is important to realize that the flower buds on apples and mountain ashes are set during the preceding growing season. This means that nothing one does in a given year will produce an increase in flowering and fruiting in that year. One must have faith that this year’s care will produce the desired results next year. And one must remember to prune and fertilize every year to keep a tree from reverting to its biennial bearing habit. Contact your county Extension office for detailed information on pruning and fertilizing fruit and ornamental trees.

A local reader wrote to ask why her bittersweet plants have failed to flower and fruit. She wonders if there are male and female plants, so that hers may be lacking a suitable mate.

As near as I can figure from reading the literature, American bittersweet is polygamous, which means that it produces both bisexual and unisexual flowers on the same plant or on different individual plants. In other words, a plant may produce only unisexual flowers and thus be unable to set fruit.

To add to the confusion, the same unisexual plant, given time, may begin producing bisexual flowers and then bear a lovely crop of berries. It seems to be a matter of maturity as well as proper growing conditions.

Our own experience with this plant was that it remained fruitless for almost a decade, but now bears quite nicely. So don’t give up on a fruitless patch of bittersweet.

Michael Zuck of Bangor is a horticulturist and the NEWS garden columnist. Send inquiries to him at 2106 Essex St., Bangor, Maine 04401.