Sunflowers wilting

Soot2006

Not sure what to do -- I work away from home sometimes. Watered my sunflowers yesterday morning before leaving and just came home to terribly wilted plants. Some look retrievable and others look downright dead. For some this is the second wilting (the first having been in March) and they are not feeling robust I think!
.... Tomorrow morning I leave again for 36 hours and worried I will lose them completely Any tips or tricks? They are standing about 50-60cm tall as growing for competition!

Soot2006

(I do have backups still in pots inside, but only standing at 20-30cm so would like to save the bigger plants if at all possible!)

valk_scot

Are they in pots or in the ground? If they're in pots I suggest you plant them out asap. Plants in the ground are always more robust when it comes to watering and sunflowers are big, greedy plants for nutrients too. If they have to stay in pots, repot them into bigger pots (I'd use a pot at least 12" across for a sunflower up to about three feet tall, then repot again), use a mix of potting compost and John Innes No3 plus water retaining granules. Also in hot sunny weather when you're going to be away for a day or two leave them somewhere cool and shady, not out in the bright and windy bit of the garden.

sammyroser

Have you put a layer of mulch around the plants? This can help in keeping the soil moist and stop it drying out in the hot sun.

I've only just found out about watering spikes. I don't honestly know how well they work but the idea is they release water slowly to your plants so might be of some use when you won't be home for a few days?

http://growandtell.wordpress.com/2009/04/24/again-with-the-watering/

This thread tells you how to make plastic watering spikes.

I've also seen some really attractive terracotta ones in my big sainsbury's. Were £2 now £1.50

Soot2006

They're in the ground, not in pots -- thanks for all the tips! I have mulched a bit, but might chuck some grass mulch on as well .... and the watering spikes.
They're looking happier today but the ones that had already wilted once back in March are definitely not doing well!