Geraniums can be stored, enjoyed again

For years, I have been purchasing geraniums to grow in my front porch planters. Then when the early fall frosts hit, I’d toss them into my compost pile, which always seemed wasteful.

In 2014, I researched how to overwinter geraniums and am here to tell you that it’s a snap. I’ve done it successfully two years in a row and haven’t lost a plant yet.

The types of geraniums you can overwinter include zonal and ivy, both of which are Pelargoniums. Here’s what you need to know:

Geraniums should be dug up before there is a frost. Unfortunately, they are typically at their best late in the season, so it feels odd pulling them up when they’re in their prime.

Place your plants on sheets of newspaper or a tarp and tap off all soil from the roots. Clip off any dead leaves, flower heads and flower buds, but leave healthy, green foliage on the plants. If you see any sign of disease, remove it.

There are two options for storing them: using a large cardboard box to store the plants together, or placing each plant in a paper sack. I’ve used both methods and have had good results with each.

If using a box, loosely stack the geraniums in it and overlap the box flaps. Don’t seal the box because you want to allow some air flow. If you opt for the bag method, avoid using plastic bags since the plants breathe, which increases moisture inside the bag and the chance of rot. Instead, place each plant upside-down in a paper sack, with the roots sticking out of the top. Loosely tie a piece of twine around the top of the sack.

Write the cultivar name on the box or sack, or place plant tags inside the containers so you will remember which ones you’re storing.

Move your containers to a cool, dark place. Since we have a basement that remains a constant 50 degrees, it’s an ideal location. Other options are root cellars or closets that stay cool. The goal is to prevent your plants from getting either too warm or frozen.

Mark your calendar to check on the plants once a month. Don’t worry that the formerly green leaves will soon be dry and brown. If you see any signs of rot, remove that part of the plant, or toss the plant altogether if there’s a lot of damage on it; you don’t want the problem to spread.

In January or early February, you’ll start seeing tiny new leaves emerging from the branches, which is always both exciting and amazing to me. Around mid-February, it’s time to pot up the plants. Use a lightly-moistened, sterile potting mix for this.

Remove the old leaves and any shriveled or black branches. Place each plant in a pot at the same level it was growing the previous year and place the pots in front of a window where they’ll get some sunlight. You’ll be amazed at how quickly they’ll turn green.

Allow the plants to grow new leaves for about a month, then trim back any leggy stems to make the plants more compact. Feed them with a weak solution of fertilizer – I use diluted fish emulsion – every two weeks. Once the danger of frost has passed, you can plant them outdoors to enjoy once again and appreciate how easy it is to recycle your plants.

Susan Mulvihill is co-author, with Pat Munts, of “Northwest Gardener’s Handbook.” Contact her at Susan@susansinthegarden.com.