Overwintering plants in a greenhouse

Hi All,

I bought three plants that are slightly too tender for my hardiness zone (USDA 8, RHS H4-H5) due to not doing enough research before buying and my friend has offered to keep them in his greenhouse. Will they need covering with fleece or should they be fine without it? And will any of them need watering?

They are Salvia 'African Sky', Salvia uliginosa and Convolvulus sabatius.

Thanks,

Nick

 

@Nikolaos Unless it turns particularly cold they shouldn't need covering with fleece in a cold greenhouse. I probably wouldn't water until spring, unless they start to wilt when I would give a little water.

 

Brilliant, thanks for that, Nigel! I suspected they wouldn't need fleece but it never hurts to check.

Nick

 

I chuck tender salvias ( amistad etc ) in a pot and leave them in the GH and dont water them till late winter spring or till they start growing. You would probably get away with most plants in H4-H5 outside. I have Uliginosa in the garden and it survived the winter ( it were quite mild last winter ) just got swamped out by its neighbours so lifted the other day.

 

This is perhaps what makes gardening so interesting. Irrespective of ones knowledge of horticulture, what books we have read etc. We all at some point ask our friends.
So so often we find ourselves perhaps underestimating the plants ability to withstand the traumas of life. I wonder. Please cast a thought back in time. The compost heap or dumpsite. Hey! That plant I dumped has started sprouting! I recall the winter of 62/3 on the plot some discarded plants had laid bare to that vicious winter, and now were showing signs of life. So overwintering plants in the GH or under other protection. Allow them to drift off into their dormant state. Gradually withold watering. Even in a GH extra precautions can be taken, such as, covering the pots etc with straw or fleece. Much of this remains a matter of trial an error.

For instance. This year. I have had a good display of Begonia semperflorens outside my front door. We have already had a couple of overnight frosts, yet the plants are still good. Most gardeners would simply pull up the plants and destroy. Me. I will lift them. Take cuttings..............cuttings this time of the year. Yes! done it before and had good results. Cuttings and rootstocks will be kept in the GH. Apart frp the bubble plastic GH insulation. This is now home for both cuttings and roots until spring.