A spider plant in a hanging basket with several brown and yellow leaves, indicating it is time to repot.

Photo: Sarah Eilers, MSU Extension

Houseplants can reduce stress and improve air quality. They deliver big benefits in return for a little water and sunshine, but may require a bigger pot for roots as they grow.

There are a few signs that a plant needs a new home:

  • Roots are growing out of the bottom of the pot.
  • The plant is rootbound, roots are dense and tangled, without room for more growth.
  • The plant is top-heavy and wants to tip over.
  • It requires water too frequently.
  • There is salt/mineral buildup on soil and/or the pot.
  • The plant is sickly and not growing well.
  • Lower leaves are yellowing and falling off.

Repotting a plant is made easier by following a few common suggestions. Plan ahead for easy cleanup. Work in an area covered with an old sheet, a large trash bag, or a potting tray.

a stack of reddish-brown terracotta pots

Photo: Adobe Stock

Select a new pot that isn’t too large: about 1/3 wider and deeper than the previous pot is a good rule of thumb. Pots can be reused if they are clean and sterile. Avoid transmitting pests or diseases by soaking a reused pot in a 10 percent bleach/water solution and then rinsing.

Different pot materials are available, and the best choice depends on a few factors:

  • Plastic is lightweight and usually less expensive.
  • Ceramic is heavier, which may be a good option for a taller plant prone to tipping.
  • Terracotta is traditional and unglazed (porous), will show mineral/salt buildup sooner, and will wick some moisture from the soil.
  • Metal containers may need drainage holes drilled or punched in the bottom.

Drainage is very important, so make sure there are adequate holes. Consider using a waterproof drainage tray underneath to collect water and protect furniture. An unglazed terracotta pot or tray will wick moisture to the surface it sits on and may cause damage.

The optimal time of year to transplant is late winter/early spring as less daylight makes houseplants somewhat dormant. However, if a plant is showing signs of stress as listed above, repot it anytime.

There are a few soil options for repotting. Premixed potting soil is available and made from different media for different plants. Cacti, orchids, and succulents have special soil requirements. You can make your own soil mix to save money if repotting many plants or to tailor soil to the plant. Lastly, you can reuse old soil. Check that soil is free from salt/mineral buildup and pests or disease, then add at least 50 percent new soil to refurbish the old.

Keep the newly repotted plant in indirect light for a few days to reduce transplant shock. It is normal to see the yellowing of leaves or leaf drop after repotting. Do not fertilize for at least two weeks to allow roots to regenerate.

Two hands holding the rootball of a snake plant above a white ceramic pot.

Photo: Adobe Stock

STEPS FOR REPOTTING A HOUSEPLANT

  1. Water the plant enough to moisten the root ball.
  2. Gently remove from the pot. If it is stuck, tap the sides and bottom of the pot to loosen or run a knife around the inside edge. If it is grown into a plastic pot, cutting the pot might be the only option.
  3. Trim off any dead, diseased, or damaged roots or roots growing out of the bottom.
  4. Gently pull the roots away from one another if they are circling the pot.
  5. If the plant is extremely rootbound, cutting the roots is a necessary step. Make sure your blade is sharp and sterile. A dull clipper will damage roots and delay regrowth. Using a sharp knife or clipper, cut into the roots on all sides and the bottom. Make cuts about a half-inch deep. Then gently tease the roots apart with your fingers.
  6. Once the plant is prepared for the new pot, place a layer of soil in the bottom (depending on pot size, usually an inch or two). Next, center the plant root ball into the pot. Gently fill the sides to about an inch from the top. Tap the pot to help settle the soil. Next, water thoroughly and let drain into the sink or a bucket. More soil may need to be added to the pot after settling. Wipe the outside of the pot to remove soil smudges and place it on the drip tray.

 

 

Jennifer Weiss is an Adjunct Professor of Horticulture at Montana State University.