Growhouse virgin.

I was given a two-tier Gardman growhouse (metal frame, plastic cover) for Christmas and was wondering when I can put my germinating perennial seeds into it to free up some windowsill space.

We only have a small garden and we're on a bit of a budget so I decided to grow first-year flowering perennials from seed - nothing fancy, just some wildlife-friendly plants to tempt the birds and bees stop by a little more often.

I'm growing Achillea, Echinacea, Lupins, Ox-Eye Daisies, Verbena Bonariensis (fell in love with it at Beth Chatto Gardens) and Pennesetum villosum 'Cream Falls' (the one with 'bunny tail' flowers).

I've not constructed the growhouse yet, but I'm wondering whether I can use it to germinate the seeds rather than using the windowsill, or whether I should wait until they've germinated before moving the trays to the growhouse, or if I'm being way to previous and should wait until I've potted individual seedlings into small pots before moving them to my new bit of kit?

Any help appreciated whatsoever.

 

Assuming you are sowing the seed in seedtrays Iain, I would suggest getting some cheap propagator lids and starting them in your growhouse.:gnthb:

 

Pennisetum vilosum is not 100% hardy - but all the others are. I would agree with David. Most would probably survive in the open now, but with plastic lids, inside a growhouse, and if you can put the growhouse against a house wall (preferably south facing - acts like a storage heater), they should get 3C or 4C extra degrees of protection.

 

I think its a bit early. The growhouse, if outside, will still be pretty cold, and that will slow down germination. Check the sowing date range on the seed packets; as you move nearer to the end date a) the plants may not flower this year, or won't put on a good show and b) you will be closer to dry periods which will stress the plants.

Conversely if you start early then the seeds may not germinate because they are cold and wet, or the seedlings may fail because of the cold (even if they are hardy).

My choice would be somewhere in the middle, particularly if a period of sunny days is forecast. At this time of the year waiting even a week brings considerably longer days and warmer temperatures.

I think 1 week of April would be ideal for seeds that say to sow from Feb/Mar to May-Jul

For anything half-hardy you'll need to do the windowsill germination thingie and not put them out until danger of forst has passed - 1st week of June to be abolsutely safe

Seeds sown on the windosill will probably take a week to germinate, and another week before they are big enough to prick out ... so that's two weeks before you have an overcrowding problem! and have to be sure that the Growhouse will be warm enough. The seedlings will apprecaite being in the growhouse during the day, if it is warm, as they willl get better light than the windowsill - so that may be a half-way option?

 

Many thanks for the replies, Peter, David and Kristen. I think what I'll do is keep germinating on the windowsills, then move seedlings to the growhouse, under a lid, once I've pricked them out.

Off to B&Q for some more lids and trays!

 

"Off to B&Q for some more lids and trays!"

Before you go ...

I bought some Garland Super 7 Spare Trays and Lids the other day (which fit my propagator) for about £10. They are quarter (I think) size and for me better than larger trays as I only want to sow a few of each - shouldn't be hard to get 50 seedlings, probably more, in a quarter tray without risk of them being overcrowded.

The Garland Super 7 propagator fits my windowsills just nicely £29.95 (different supplier)