How was your weekend? I spent some time looking through photos of summer gardens this weekend for inspiration , & I’m pretty excited about the flowers I’m going to grow.
Last time I wrote about growing half-hardy annuals, plants that grow, flower, set seed then die in a season. This time it’s all about growing half-hardy annuals (HH’s) from seed, the more tender cousins of the hardies.
Please don’t be put off by the thought of tending delicate plants, HH’s are brightly coloured, fast-growing & very glamorous. In short, they make your garden sing & essentially, they just need planting later than hardy annuals.
Zinnias:
They remind me of French markets where you see bunches of them being sold along with vegetables.
Zinnias reach 30-90cm tall, & come in a range of zingy colours.
Sunflowers:
I’m still amazed that all this grows from seed in a few weeks.
Cosmos:
Cosmos grow to 50-90cm tall depending on the type, & flower for months. See how the bees love them.
How to sow half-hardy annuals:
They originate from warm climates, like Mexico, so they need to be sown & kept in a greenhouse, or on a light-filled window-sill & planted outside after all frosts have gone.
I sow them here in mid-April, 6 weeks before the last frost date, at the end of May.
square pots fit neatly into trays & don’t wobble around
- Fill modules or trays of 3 inch pots with good quality compost & water them.
- Thinly scatter the seeds over the surface of the compost.
- Cover with a thin layer of compost or grit & add the label.
- Then cover with a couple of layers of newspaper, lift & check daily & remove the paper when the seeds start coming through.
- Water gently if the soil starts to look dry, & turn them towards the light if they start leaning to one side. Probably every day on a window-sill.
Hardening off:
They need to gradually acclimatise to outside temperatures before being planted outside permanently. The contrast between night & day can be too much of a shock. Placing them outside in the morning& bringing them back in at night gets them used to being outside. It’s easy if you have them in trays or they can be moved to a cold-frame & the lid opened each day.
At first this seemed like a bit of a faff, but now I think of it as relaxing pottering, especially at the end of a busy day.
Planting:
Plant them outside in a sunny spot, but do it in the afternoon when the heat of the sun has gone [remember what that was like!] so the change is not too much of a shock.
Remember to water them regularly when they’re young, & they’ll grow very quickly. They have to because they’re on a mission to produce seeds before they run out of time.
The seeds can be sown directly into the soil after the frosts, I did this with the zinnias I grew at the allotment. However, they’ll flower later & if the tiny plants are eaten by slugs or snails, there won’t be time to grow more this year.
More half-hardy annuals:
Cleome [spider plants] usually in whites or pinks, grow up to a metre tall & last well as cut flowers.
Nicotiana [tobacco plants] I like the lime-green & deeep red ones.
Buy seeds from Higgledy Garden here & see how to grow annuals from seed here & how to plan ahead, what containers to use etc here.
Any thoughts on growing half hardy annuals?
Jill
all photos: Jill Anderson
Cosmos are definitely on my seed list this year, Jill. I like the look of ‘Antiquity’ from Chiltern Seeds, it’s a dusky rose if the photo is to be believed. I love zinnias when I see them but am never sure where they might fit into a garden’s colour scheme – I might have a go at growing them among the veg or up at the allotment. Whenever I look at the choice of flowers available as seed, I wish I had three times the growing space to accommodate a greater selection!
Hello Caro, yes it is all a bit overwhelming at times & hard to leave things out. I’m going to be strict with myself this year! The allotment is the perfect place for zinnias, very French! Cosmos Antiquity sounds lovely, the good thing about Cosmos is that they flower for so long!