How to . . . grow hardy annuals

by Rhiannon James

credit: Phyllis Buchanan

Hardy annuals are fast fashion for the garden: they’re cheap and only last for a season so they’re a great way to experiment and have some fun. You can use them as a quick fix for empty flower beds – so they’re perfect for new, rented and guerrilla gardens – but also to plug the odd gap amongst permanent plants and to add big bursts of summer colour to containers.

There’s a huge range of plants to choose from, including native wildflowers, climbers, flowers for cutting and even edible options such as nasturtiums, and they’re all really easy for urban gardeners to grow. Seeds can be sown straight into the soil so indoor growing space and propagation equipment aren’t needed and you won’t have to spend time on jobs such as transplanting and hardening off.

Sowing is best done when the soil is warm and moist, usually from late March to May but some hardy annuals can also be sown in the autumn so they flower earlier the following year – check seed packets for timings for specific plants.

Things you’ll need

1. A piece of paper and a pencil

2. A garden fork or a border fork

3. A garden rake

4. Some horticultural sand or a cane

5. A small hoe if you have one but this isn’t essential

6. Packets of hardy annual seeds such as pot marigold, cornflower, nigella, California poppy, corn marigold, sunflower, corn cockle, cleome and many more. When picking your seeds, it helps to think about flowering period and eventual height as well as colour, shape and other benefits such as wildlife value and scent.

7. Plant labels and a permanent marker pen


1. Start by picking a spot in the garden to plant your seeds. The area should normally be warm and sunny, have well-drained soil and be sheltered from cold winds.

2. If you’re planting a whole area with hardy annuals and you want to create a meadow-style effect, you can use a mix of seeds and sow it across the whole space.

If you’d like more of the feel of a flower border however, then it helps to make a plan before you start. On a piece of paper, draw a rough outline of the area you’re planning to use. Then divide it up into sections, including at least one for each plant (or combination) you want to grow. For a more naturalistic effect, use drift-like shapes with flowing, irregular outlines. Then label your plan to show which plant will go where. It helps to check the heights of the different plants when you do this – shorter ones should be nearer an edge where they can be seen but you might want to avoid creating regimented steps from the front of the bed to the back. You’ll also need to think about any colour or other combinations that you want to create. If you’re just filling a few gaps in the garden or sowing in small containers, then there’s no need to spend as much time on planning.




3. Ideally, large areas of bare soil will have been dug over in advance to remove weeds and loosen up the soil but if that didn’t happen or wasn’t practical, don’t worry. Loosen the soil with a fork if necessary, removing all weeds, sticks, large stones and clods, and then leave it to settle. Try to avoid working or walking on the soil when it’s wet because this can cause compaction.

4. Pick off any weeds and debris. Then rake over the whole area to create a roughly level surface (a balanced fertiliser can also be lightly raked in if necessary), tread light soils to consolidate them and rake over the soil again until you get a fairly fine texture or tilth.

5. Using horticultural sand or a cane, draw out your planting plan on the soil surface.

6. Then you can start sowing your seeds –a day when the soil is moist but not wet is ideal. There are two possible approaches to sowing. You can either scatter the seeds evenly across the surface of the soil (a method called broadcasting) or you can sow them in shallow channels or drills. The advantage of using drills is that you’ll easily be able to distinguish between hardy annual seedlings and young weeds so you won’t be in danger of pulling up the wrong thing.

Use a small hoe, a cane or the corner of a rake to make parallel furrows of the right depth (this information is usually given on the seed packet) in each section of your planting area. If you make the drills in one section perpendicular or at an angle to those in the adjacent ones, the plants will not look like they have been planted in rows when they’re fully grown. It also gives a more natural feel if you let seed spill over into some of the neighbouring sections. If the soil is dry, water the furrows before you start sowing. Then, thinly and evenly sow the seeds into the bottom of the drills and cover them with soil. Small, fine seeds can be trickier to handle – try tipping some into the palm of one hand and, taking a pinch of seeds with the other, gently roll them between your index finger and thumb so they fall fairly evenly into the drill.

If you’d prefer to use the broadcast method, rake across the soil surface to create furrows, scatter the seeds evenly over the area and then pull the rake over again, but in a perpendicular direction to the furrows, to cover the seed with soil.

In containers, fill each pot with compost and then water to create a moist environment for germination. Sow the seed over the surface and add a thin layer of compost (check the planting depth suggested on the packet) on top.

7. Then label each section or container with the name of the plant and the sowing date.

8. Try to keep the soil moist but not soaked. If seeds and seedlings dry out, or sit in soggy ground, they won’t prosper.

9. Once seedlings have appeared, thin them (pull out the weakest-looking specimens) until you get to the spacing recommended on the packet, trying not to disturb the roots of the plants you want to keep. Although thinning feels a bit like wasting plants, it’s important to keep doing it as overcrowding is one of the most common causes of a below-par display.

10. Check if any of your annuals will need staking to stop them being flattened by wind or rain. When these plants are a few inches high, push in some canes or other supports ready when for when they’re needed.

Then all that’s left to do is to keep down weeds, water in dry weather and wait for a blooming summer display.


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