, Newburyport, MA

February 6, 2013

Tim's Tips: When re-potting a plant, measure correctly

Tim's Tips
Tim Lamprey

---- — This week will be a potpourri of things you need to know for this time of the year.

During the last two weeks, I had many people come into the store with houseplant problems. The problem concerns insects on the houseplants. In most cases, the plants had been outside last summer and then were brought back into the house. While outside, they were exposed to many insects, but natural predators kept the insects in check. Once the plants were inside, the insect population began to grow due to the lack of natural predators. At this point, an application of an insecticide will get the insects under control. Depending on the type of insect, you may find that using a systemic insecticide may be your best bet.

Most of your houseplants will soon go into a period of new growth. Some will need to move up to a larger size pot. If you are not sure whether or not to repot your houseplants, take a few moments to do a quick test. Slide the pot off the root ball of the plant and then look at the roots. If the roots are white along the outer edge of the soil, then the plant doesn’t need to be repotted. If the roots along the outer edge are brown, then it is time to repot.

If the plant needs to be repotted, you will need to measure the size of the pot across the top. You want to increase its size by one to two inches in diameter. If the plant is in a small pot, say 4 inches across the top, then you want to use a 5-inch pot when repotting. If the plant is in an 8-inch or larger pot, then you want to use a pot that is 2 inches larger.

Some people will make the mistake of moving the plant from, say, a 4-inch to an 8-inch pot. People usually do this because they think it will allow the plant more room to grow. The problem is that all that extra soil around the root ball stays wet until the roots move out and fill that extra soil. Overly wet soil will lead to the death of the roots. When moving houseplants to a larger pot, moving them up to a slightly larger pot is always the best way to go.

We have experienced some tremendously strong winds during the last few weeks. These winds may have caused some damage to the trees and shrubs in your yard. You should take a few moments to go outside and inspect this area. If branches have been damaged, you may need to do some pruning to remove them. If the damage is not taken care of soon, there is the potential for more damage to strike those plants during the next windy period we get this winter.

Well, that’s all for this week. I’ll talk to you again next week.


Tim Lamprey is the owner of Harbor Garden Center on Route 1 in Salisbury. His website is Do you have questions for Tim? Send them to, and he will answer them in upcoming columns.