Sowing Half-Hardy Annuals in April

It's now time, in mid-April, to sow your half-hardy annuals for lots of colourful blooms this summer! Hooray! 'Annuals' are plants which grow, bloom, set seed and die within the space of a year and 'half-hardy' means that they are not frost tolerant and need a little more warmth to start growing. By the time they've germinated this current cold snap will be over and we'll hopefully have some warmer temperatures, which will be perfect for them to shoot up.  You'll still need to protect them from the frost though - if they are exposed to it they will die - so you'll need to keep an eye on the weather. Here in Surrey, our last frost is usually around the middle to end of May, so you'll have to keep your half-hardy plant babies safe for another 4-6 weeks until you can plant them out.  This is the reason it's a good idea not to sow them too soon - you end up with huge, spindly plants on your windowsill and nowhere for them to go.  If you start them now, either in a greenhouse or on a sunny windowsill they'll be the perfect size to go out when the frosts are over.

Here are a few of my favourite half-hardy annuals that you might like to try - guaranteed to give you lots of flowers and feeds the insects too:  Cosmos, sunflowers, zinnia, marigolds and nasturtiums.  And don't forget to try some vegetables too - a tub of tomatoes, or some salad are easy and satisfying to grow. 

So, get down to the garden centre and choose yourself a few packets of half-hardies and get sowing.  The method for sowing them is just the same as for hardy annuals (plants which are frost tolerant and can stand the colder temperatures of late winter and early spring) so do take a look at my previous posts which show you what equipment you need and how to actually sow the seeds.  The only difference is that, unlike the hardy annuals, you can't plant them out in the garden until all chance of frost has passed.  If you don't have a greenhouse and don't want to have seedlings on your windowsills you can plant some half-hardies straight out into the ground from late May but they will flower much later in the summer. 

I'll be doing a post next week on planting hardy annuals out into the garden as I think it's going to be warm enough then to do so. I can't wait to clear a little bit of space in the greenhouse - whoops, yoga studio! - I need those shelves for the seeds I'm sowing this weekend! Happy gardening :-)



Repurposed takeaway coffee cup from my local cafe, now home to a tomato plant on my office windowsill



Cosmos - easy to grow, food for the bees, perfect for the vase and beautiful in the garden