Overwintering Tender Succulents

Succulent garden in summer

I fell in love with succulents a while back.  They come in such a variety of shapes, colors and sizes.  They are very low maintenance, and with proper care, they can live for many, many years.  You can't beat a deal like that.  I even built a raised bed and filled it with very sandy loam so that I could keep Hens and Chick alive.  They don't like our heavy clay soil, so after about the 4th time Mom gave me "chicks" from her patch, only to find them dead the next spring, I decided to take action.  They love that sandy loam and bloom heartily and produce many chicks each year.

 That challenge mastered, I decided I needed yet more succulents.  Well, other than many sedums and the native pasture cacti (from which I have already picked enough  stickers out of my feet and hands and have no need to grow them in my garden, thank you very much), there aren't a lot of succulents hardy enough to survive our winters.  So, I created movable gardens - they move outside in the spring and inside in the late fall.

The tricks to overwintering them successfully indoors are really the same as growing succulents anywhere, anytime - don't over or under water them; fertilize as needed; and give them the right amount of light and warmth.

Succulents need a good deep watering about once a week while they are actively growing.  While they are in dormancy, they should be watered when the soil is dry to the touch.  For the containers I store in the cool garage, that means about once a month.  For those in the warmer house or garden house, it means once every week or two.

I begin preparing the succulents for the winter in late summer to mid-fall.  I feed the succulents half strength all purpose fertilizer (10-10-10) every couple weeks during their active growing season.  I give them one last feeding about the last week of August, just before they begin to respond to the cooler nights and shorter days by going into dormancy.

My hardier tender succulents spend the winter in the garage, which is maintained at about 50 degrees.  Succulents will survive on just three to four hours of indirect light while they are dormant, so they are perfectly happy setting in front of one of the garage windows.  A word to the wise about garage overwintering in North Dakota - you do need to set your succulents far enough away from the big overhead doors so they don't get that blast of frigid air every time you drive your car in and out.  I have mine set behind some storage cabinets that separate the car parking area from the storage area.  Any kind of a screen will be effective, though, as long as you don't leave that door open too long.

When I water the dormant succulents, I add water until it starts to drain from the drainage holes in the pot.  It is important that you water them deeply, but far less often, in the winter.  I use rain water that I've saved and stored over the winter, but you can also use de-chlorinated tap water.  Simply fill an open container with tap water and let it set overnight before using it.

Each time I water, I check the succulents carefully for any signs of bugs or rotting stems.  Rotting stems is an indication that the plant is too cold or too wet.  Trim the bad stems off;  reduce the watering; and check the temperature to make sure it isn't getting below 50 degrees.

The most common insect pests are aphids or mealy bugs.  Aphids are known by the "honeydew" they leave on the plant stems and leaves.  Mealy bugs look like little white cotton balls, found mainly in the stem junctures and under the leaves.  If you see signs of either of these, you can wipe the foliage with a cotton ball or rag soaked in 70% rubbing alcohol wherever the infestation is evident.  An easier way to accomplish the same thing and even get rid of those pests who are lurking where you can't see them, is to fill a spray bottle with three parts 70% rubbing alcohol and one part water and spray the entire plant with the mixture.

Infested plants should be separated from healthy plants to control the spread of the insects.  I believe in prevention, so I will generally give a good spray to even those plants which aren't currently showing active signs of insects - mealy bugs especially like to hide where you don't notice them until they've become pretty pervasive.  Then, I check all the plants weekly and repeat the treatment as needed.

As the days being to lengthen, generally in about mid-March to early April, I start to prepare the overwintered succulents for the move outside once the temperature remains 50 degrees or above.  I place them under grow lights, for increasing hours each day, until I get them from the three to four hours per day to which they've become accustomed, to the twelve to fourteen hours they'll receive once they are back outside for the summer months.  If you don't have grow lights, you can accomplish the same conditioning by moving them to a sunnier spot and the increasing day length will take care of itself.  Just be careful not to move them into too much too soon, whether that is warmth or direct sunlight.  They will be pretty tender after spending so much time in the darkness of winter.

Next week, I'll begin talking about the various types of succulents that I've found to do well in containers.