I have noticed that some crabapple trees have suckers and some don’t. I’m guessing that certain types are more likely to have them than others. I’m talking about the shoots of growth that come from the base of the trunk and sometimes come from the roots out away from the trunk. I have been told that there is nothing that can be done to prevent these suckers and the only thing that you can do is cut them off. I have also heard that cutting them only promotes more growth and they should be torn off. I have a great-looking crabapple, but it grows many suckers and some of their bases have become so thick over the years that they are difficult to cut and impossible to tear off. The reason I’m asking is because this tree needs to be removed from its current location. I hate to just cut it down, but it seems like there are always suckers that need to be removed. If I have it moved to another location, is there anything that can be done to prevent or reduce the number of suckers?

You might not realize that flowering crabapple trees are nearly all self-sterile. One way they are propagated is through grafting soft “whip” to a winter-hardy rootstock. Those rootstocks are what cause the suckers. Older rootstock selections were bred primarily to withstand Michigan winters. Hardiness was of prime importance to the fruit grower.

However, over the last 40 years, there have been substantial improvements in rootstocks that not only produce good root systems and are easy to transplant, but are relatively sucker-free. These are the Malling rootstocks, developed in England, and are used extensively by nursery growers today. Your crabapple may pre-date the use of the Malling series.

Another factor is how heavy your crabapple has been pruned over the years to maintain its pleasing appearance. A rootstock more prone to producing suckers will respond to hard pruning with a veritable army of soldier-like sprouts. The plant’s response is to send up as many opportunities as it can to regain leaves which produce its food. This response could be accentuated if the hard prune was done in early spring instead of late winter when the plant would be at its dormant best. Actually, stimulating root suckers, or “stooling,” is one of the ways new multiple rootstock plants are created.

It appears the heritage of your rootstock is the primary source of the problem, and unfortunately, you cannot change that. Since the tree must be moved from its current location, it might be better to remove it completely and replace it with one of the newer cultivars developed on one of the improved Malling rootstocks. If you are especially fond of this tree, you could also have a certified arborist, knowledgeable about grafting, take a softwood cutting and graft it to an improved rootstock that will not produce a sucker response to every pruning. (There are also products currently available on the market containing growth hormones which can be used to help control sprout and sucker growth on woody ornamentals.)

However, if you choose to replace the tree with a variety similar in height, blossom color and fruit, seek out a reputable nursery and specifically ask about the rootstock they use. With the tremendous number of cultivars available, there will certainly be a crabapple that mimics the look of your old one, but with none of its aggravating attributes.