Question
I have a large[about15inches] pot outside growing a mandevilla. This is my first summer and do I need to take this in for the winter,living here in Lansdale pa as it goes below freezing here in the winter. It has grown lovely and beautiful. Appreciate what decision to make for the winter. Thank you, Flo

Answer
Florence,

Yes you will need to take it in before frost. As the nights begin to cool off the Mandevilla will slow down. That is the time to give them some food to harden them up for the long winter.

Try to use a liquid fertilizer with a high middle number e.g. 10-56-14, (Give i/2 the amount the container says.) since you can cause fertilizer burn. We are not trying to promote growth but to toughen the plant up. Don抰 go over board with the fertilizer; let the plant stay outside as long as possible. It should be able to handle high 40抯 for brief periods. When nights start going to the low 40's you need to take it in.

After about 3 weeks (if you can hold out that long weather permitting) prune the plant back. Not just tipping the plant but cutting it down to about 12 inches above the soil line. I would also treat this vining plant for any possible pests problems since it will be going indoors for the winter.  If you have a place that you can take it in that does not freeze but gets cool, like an unheated garage or an unheated cellar.

Next we want to begin slowing up on the water and let the plant run on the dry side. Remember that we have given the plant some fertilizer and removed a lot of growth so the requirements for water should drop.

When you bring the plant inside place it in as much light as possible. You are looking for maintenance not growth. You抣l probably get some quick new growth, just try to maintain it. Some people place the plant in a clear plastic bag and over wintered their Mandevilla in their heated garage.

Try to maintain the plant on the dry side throughout the winter. The cooler the location that it is stored in the less water you should give it.

When spring comes you can move the plant outside. Expect the growth produced during the winter to be burned off!!!

Although, I cannot guarantee the above method will work you, it is a guideline that has worked for others over the years you can try.

I hope that helps? Let抯 me know how you do. Good luck!!!!

Darlene