growing annuals for cutting

breezyacre · Posted: Sun Apr 05, 2009 5:29 pm Post subject: growing annuals for cutting

Saw a great article by Jane Powers in yesterday's Irish Times mag. about growing annuals for cutting in the garden. Anyone have any advice on this. I tried some cosmea in the tunnel last year but it was very late to flower. Could it have been the lack of sunlight and heat last summer. Have just bought some more cosmea and cornflower and dwarf sunflower. Am tempted to give some space to them in the tunnel again as my site is windy and can be cold. Any thoughts on this would be gratefully received. Shocked

Liparis · Posted: Sun Apr 05, 2009 9:29 pm Post subject:

It could actually be too hot. Inadequate ventilation and cooling can make plants stop growing as a survival tactic. It slows down respiration so they don't lose water too quickly. Usually annuals need to grow outside unless they are tender annuals. Very few plants grow at temperatures higher than 85f (aproximately 29.5c) unless they are adapted to it, by that I mean in nature. It's easy to acclimatise plants to cool conditions but extremely difficult to acclimatise to higher temps.
Poly-tunnels can get very hot if in the sun, even a couple of hours in direct sunshine can raise the temps up to 100f or more. This would stop the plants growing for several hours each day that happened.
Poly tunnels with a mesh skirt along the bottom are more efficient, they allow very good air circulation, especially in conjunction with mesh doors in either end. A poly skirt can be dropped into place to stop cold drafts on cold days.
Bill.

Sive · Posted: Sun Apr 05, 2009 9:35 pm Post subject:

It's hard to beat sweet pea......make sure you sow the really scented ones. Cornflowers are magical....the most stunning blue and they flower endlessly right into the winter.....I threw a packet of cornflower in to a bare patch last year, and in spite of our hilltop wind and awful summer I had flowers right up to Christmas.
Maybe it was all beginner's luck!

breezyacre · Posted: Mon Apr 06, 2009 9:21 am Post subject:

Thanks to you both. I leave the doors of the polytunnel open all the time in the summer for ventilation. The doors I have are old louvre doors off an old wardrobe so there would be good circulation always. I have never really been successful with cornflowers straight into the ground. Maybe I didn't plant them early enough. I always waited to well into May.

breezyacre · Posted: Mon Apr 06, 2009 11:55 am Post subject:

Am tempted to plant some seed today. Cornflower and cosmea. Packets do say spring. Anyone any opinions?

verge · Posted: Mon Apr 06, 2009 12:53 pm Post subject:

In a tunnel you should be ok with both now breezyacre.