Propagating and growing white geraniums

This year we had a problem in that some careless person left the greenhouse door ajar on a 15 below zero night. How anyone could be that stupid is beyond me. I thought I closed it tightly but I guess I was wrong.

The door is made of aluminium and when it is 15 below zero outside and 75 inside condensation forms on the door and turns to ice. The ice prevents the door from closing properly. We have tried insulating the door but it does not work so the only thing we can do for now is chip the ice away. Hopefully we will not have too much more really cold weather but you never know. This summer we intend to replace the door with something more substantial.

Anyway today we continued propagating and growing white geraniums. It is a miracle that we had any to work with because the plants we wanted to cut from were in the direct path of the sub zero temperatures that got into the greenhouse that fateful night.

There were only enough from other plants that were not affected to make 15 pots. The rest we started from small growing plant ends, most about 1 inch long.
We started by taking cuttings that were new growth and that had more than 3 nodes. The bottom node is split to expose as much of the natural growth hormone as possible. For extra insurance we use rooting hormone.

The starts were placed in wet ProMix 608 flats. That is 6 packs that make up 48 cells to the flat. and we kept them wet. It has been a little more than 2 weeks and many of them have nice roots. A craft stick can be used to gently lift the plant from the cell to look for roots. They will be obvious and the small ball of soil will be held together.

For the ones with the roots, we transplant them into square 4 inch plastic pots using ProMix. It is amazing how big they look after being transplanted. The flats are put in a shady spot and kept slightly wet, not saturated. We want the plants to be able to take up water but we do not want to rot the roots.
The starts did really well and part of the reason is we are directing heat below the benches. This keeps the soil in the pots and flats warm and the plants seem to like warm feet when they are making new roots.

Once the plants are firmly rooted in the 4 inch pots we water them as a growing geranium, that is we allow them to slightly dry out between watering. I guess it is because the geraniums are similar to a succulent that they benefit from being allowed to dry out. As a matter of fact we have kept mature geraniums in the cellar all winter with a very small amount of water, maybe once a month.

In the spring the plants are trimmed back and given water and some times re-potted. After months of little water the soil becomes dried out and will not hold water or nutrients very well. They seem to bounce back and its a good way to keep from having to buy the same plants year after year. Instead new specimens can be added to the collection.

At this writing we have white, red zonal, zonal peach, variegated green, Mrs Henry Cox, distinction, variegated yellow and green, crispin, small citrus, apricot, mint, citronella, chocolate mint, lemon, pink ivy, black ivy, red ivy, purple ivy, many seed varieties, about 8 different Martha Washington’s and probably a few more I missed. There are most likely more than 30 kinds of geraniums growing now in the greenhouse but we are always looking for more.

We are definitely going to have more greenhouse space very soon.