Repotting Procedure Is Worth Repeating
Container growing has been around for centuries. Ancient Egyptian hieroglyphics show plants growing in containers. Much of their revival is attributed to a compression of garden space.
Most plants growing in containers benefit from repotting. This is a good time to check because spring transplanting also tends to stimulate new growth.
Plants that appreciate larger quarters usually will provide ample clues. Look for such things as discolored or yellowing leaves; roots coming out of the drain hole or growing exposed on top; a plant that wilts frequently and needs daily watering; or water that runs out of a pot as soon as applied. Those are symptoms of a pot-bound plant.
A secondary benefit of spring repotting is the opportunity to reassess the placement and number of outdoor containers:
Can the plants be grouped into larger containers? Too many small containers are a guaranteed maintenance nightmare.
Did the plants seem to suffer last year in the afternoon sun? Did the containers get too hot? Is a shift to morning sun feasible?
Many houseplants can be root and top-pruned and returned to the same pot after adding fresh growing medium. This also helps keep them small enough for indoor culture.
Some old practices, such as covering the drainage hole with broken pieces of clay pots or stones, now are questioned. Most gardeners use a hunk of sphagnum moss to cover the drainage hole.
Repotting used to be called “shifting”--transferring a plant from a small to a larger pot--and the rules were pretty inflexible. Only the next-size pot could be used: A plant growing in a 3-inch pot had to be moved to a 4-inch pot.
Now the process is more flexible, although many of the old practices still are good basics.
* Pots need to be clean.
* Try not to move plants while the ball of soil is wet; wait until it’s dry enough to crumble.
* Plants should never be reset deeper than they were growing originally.
* Foliage should be pruned to match any loss of roots in transplanting.
* If the plant did well in the old container, stick with the same type--plastic or clay.
However, in the home, a plant should survive just fine if moved from a 2-inch to a 4-inch pot or from a 4-inch to 6-inch container. Just don’t give them too great a shift. That can create drainage problems. (The size of a pot, incidentally, is measured by its diameter at the top.)
Remember too that hardwood plants such as azaleas, roses and palms are trickier than softwood ones such flowers to transfer.
It’s also wise to standardize on the growing medium. A good mix will drain well, hold water, have sufficient nutrients and allow oxygen to penetrate.
Garden soil, even if topsoil, is almost certain to be a headache in containers.
Most container mixes are soil-less types, based on equal parts of sphagnum peat moss, perlite and coarse sand, plus fertilizer and lime.
For cactus, try half peat, 40% sand and 10% perlite.
A slow-release fertilizer is good insurance with a soil-less mix. If you are repotting only a few plants, it’s usually simpler to buy a commercial mix.
To get the plant out of a container, turn it upside down, hold it firmly with one hand and tap the rim sharply on a solid surface.
Cut the root ball on the sides and bottom, about one-quarter inch deep, and lightly rough it to induce the roots to break from the dimensions of the old pot.
Put sufficient growing medium into the new pot so the plant will stand about an inch below the rim with the soil level about the same as it was originally. Jam the new mix around it. The thumbs are perfect for this.
Then water until it comes out of the drainage hole.
