Maple seeds sprouting in a lawn. Photo: Ken Bosma, www.flickr.com
Question: We have a red maple that produces hundreds of seeds every summer and most seem to grow in our lawn. Is there a way to stop this production?
Answer: No, you can’t stop a tree from producing seeds. There is no hormonal spray or injection or chemical treatment you can apply to stop this natural phenomenon from occurring.
When a tree reaches full maturity (and that can take years, even up to two decades in the case of some species), it will start to flower and there is nothing you can do to prevent it. If, when it blooms, the flowers are pollinated (and how could you possibly prevent the wind—for anemophilous plants—or insects—for entomophilous plants—from pollinating the blooms?), there will be seeds, probably hundreds or even thousands of seeds, depending on the species of tree. And if there is a lawn nearby and the seeds land on it, it’s very likely they’ll germinate and seedlings will start to grow.
The only solution would be to cut the tree down … a bit drastic, don’t you think?
If you want to plant another tree and don’t want to have to deal with seeds sprouting everywhere, there is an easy solution: plant a variety that doesn’t produce seeds.
In the case of dioecious trees, such as poplars, willows and even some maples, there are male and female trees. So, you just have to plant a male tree: it will never produce seeds. (But be forewarned: male trees are often a major cause of hay fever!)
In the case of monoecious trees (which have male and female flowers on the same tree), there are sometimes sterile or nearly sterile cultivars that either don’t produce seeds or fruits or produce so few it’s not a worry.
Just Mow ’Em Down!
I must admit I really don’t quite understand your concern about the tree seedlings sprouting in your lawn, because just mowing the lawn, something you have to do anyway, will chop the top off the seedlings and bring about their demise, solving the problem. I’ve mowed lawns almost my entire life and this solution is foolproof!
Young tree seedlings are always tall enough to be quickly clipped down by a mower. And when they’re cut back, seedlings that young don’t have the energy reserves they’d need to grow back.
So, if the appearance of tree seedlings sprouting in the lawn bothers you, just mow a little more often!
Trees Seeds in Flower Beds
Tree seedlings that sprout in a flower bed or vegetable patch, or come up through a ground cover or mulch, are more difficult to manage. For one, you obviously can’t mow them! They must be pulled out or cut manually.
Since young seedlings haven’t had time to grow much of a root system, they’re easy to yank out. And the still very tender stems are easy to clip off. Just make sure you cut below the cotyledons, thus leaving no leaves at all. If you get them the first year, there will be no follow-up.
Second-year seedlings are more tenacious. Their more abundant roots make them harder to pull and many, depending on the species, are able to grow back from the base if you clip them. That’s why it’s important to eliminate them the first year, when they’re still young and fragile.
Trees that bloom on year old stems will not bloom if pollarded. I certainly do not recommend pollarding (unless a pollard is actually desired), but that is why certain types of trees are commonly pollarded. It is sort of a cop out that ruins the trees (unless of course, a pollard is actually desired). Many trees produce more viable seed in response to distress.
I wish you hadn’t mentioned that. I just think pollarding is such a bad idea so many reasons!
Oops. I happen to like it for the production of juvenile eucalyptus foliage, and for certain other applications, but it makes me cringe to see other do it improperly, . . . and with only one exception, they are all done improperly. That one exception here is a historic sycamore that is pollarded very well in the English style. I still do not know who does it, but he or she obviously knows how to do it.