What to do when 'suckers' sprout from the base of a tree
Gardening columnist Don Kinzler addresses how to remove trunk suckers or basal suckers, and also answers questions about reworking a perennial flower bed and mulching around a tree.
Q: I have a few trees in my yard that have growth at the bottom as shown in the photo. Should I cut the sprouts down? If so, what's the best way to do it without hurting the tree? — John A.
A: The branches sprouting from the tree base are called trunk suckers or basal suckers and are best removed so they don’t form a bushlike structure around the tree. Suckers are common on some tree types such as apple, crabapple, tree lilacs and lindens, including basswood, which is likely the tree in your photo.
With a pruning shears, cut each sucker sprout back to its point of origin at the trunk or the soil near the trunk. Prune each sprout as flush as possible, so little stubs don’t remain, as they can more easily resprout. Sucker sprouts can be removed whenever they appear, which is easier when they’re tiny.
On trees that tend to have basal suckers, resprouting is common. Preventative product such as Sucker Stopper or Sucker Punch can be tried, but directions must be followed closely for best results.
Q: I have a perennial bed that includes tulips. It’s overgrown and needs redoing. Do you have a recommendation on how to salvage the tulips in this process? I'd like to work up the soil if possible and basically start the bed from scratch. — Twila N.
A: Luckily, tulips go dormant by midsummer, so this is the perfect time to dig and relocate them successfully. Hopefully the remnants of dried brown leaves are still visible, so you can find the tulips in the perennial bed.
Here’s what to do: Dig the tulip bulbs, spread them out in shallow trays and store in an airy garage that won’t get excessively hot. Tulip bulbs can be held in this dormant condition while you are reworking your perennial bed.
Plant the bulbs in September or early October in your newly renovated perennial bed. Water well after planting, because the bulbs produce roots in the fall in preparation for next spring.
Q: We are going to put mulch around a large weeping birch that has lawn around it and are wondering about the grass removal. It appears to be a lot of work to remove the grass! Is there anything that can kill the grass without hurting the roots of the tree, some of which are exposed? — Andrea R.
A: Mulching around all trees is a wonderful plan, especially birch, which require cool, moist soil for best performance.
There's no need to kill the grass or remove it. The following is a method that’s worked wonderfully for me.
First, mow the grass around the tree as short as you can. Then place a layer of flattened cardboard directly on the grass, overlapping cardboard sheets by at least 2 to 3 inches at the edges, so grass won't grow between the cracks. Place the cardboard pieces so they form a circle around the tree, preferably at least 5 feet in diameter.
Next, cover the cardboard with 3 to 5 inches of shredded wood mulch. The cardboard prevents grass and weeds from emerging through the mulch, and the grass will decompose naturally below the cardboard.
The cardboard will eventually decompose into a thin compost layer. Keep the wood mulch at least 3 inches away from the tree trunk. I've used this method for years with fantastic results.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at firstname.lastname@example.org. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.