Monty Don shares his recipe for success for brilliant summer blooms

Get Monty Don’s top tips on planting the flowers that will brighten your summer borders

pink and white cosmos flowers in an English country garden
(Image credit: Rosemary Calvert/Getty Images)

For a garden rich in color and interest this summer, you’ll likely want some tender annuals in the mix, whether they’re going into borders or containers. Once the risk of frost is passed and with a period of hardening off, plants like sunflowers and zinnias can go into the garden.

But what do you need to consider to give these beautiful flowers and more a successful start? Enter our favorite gardener Monty Don who’s been giving his advice on planting tender annuals now May is here.

For Monty’s top tips, all you need to do is scroll down. And for more inspiration on planning, designing and planting your flowerbeds, check out our guide to garden borders.

Monty Don’s top tips on planting tender annuals

Zinnia Zahara double mix

Zinnia Zahara double mix

(Image credit: Thompson & Morgan)

Monty Don gave the lowdown on planting tender annuals on his website. We’re sharing his top tips below, along with our own advice.

1. Annuals may go through their entire life cycle in just one season, but they’ll create a wonderful display of blooms during that time. The tender sort need temperatures of above 5ºC (41ºF); if the mercury falls, they may suffer damage or even die.

The upshot is that you need to get the timing of planting right when it comes to tender annuals like cosmos, tobacco plants, zinnias and sunflowers. Monty advises that they can be planted out by the middle of May in all gardens except the coldest. You can find out how to grow sunflowers in our guide. 

Which other blooms might you want to put in now? Consider nemesia and marigolds, too.

2. Make sure you harden these flowers off for at least a week first, though. This process will mean both faster growing and longer lasting flowers, Monty says.

Annuals from a garden center are likely to have been kept sheltered to create a good display, according to Monty. If you’re buying over the next few weeks, therefore, don’t plant them out right away. Instead, Monty recommends putting them in a sheltered spot in the garden so they can acclimatize.

how to grow sunflowers

(Image credit: Future)

3. Monty doesn’t use tender annuals as bedding plants – that is to provide a seasonal display and even a formal look using straight lines and symmetry. Instead, in his garden, they are there ‘to enrich the general tapestry of the overall planting’.

This means a different approach. If you want to follow Monty’s lead, don’t plant in straight lines, but place your annuals in groups to create drifts and clumps as part of your flowerbed ideas.

Planting this way can create an impact and, in terms of garden design ideas, it has the effect of giving the eye somewhere to focus rather than trying to take in an eclectic array of blooms. Do make sure you size drifts and clumps to the bed when you’re putting them in, though, opting for smaller numbers for narrow borders.

4. How far apart should your annuals go? Monty recommends a distance of around 30 to 45cm. The other essential, according to Monty, is a sunny spot that isn’t exposed to strong winds. Once planted, water in well, he advises.

5. The results of your efforts should be annuals that thrive and flower into the autumn, he says, provided the temperature doesn’t fall below 5ºC (41ºF).