How to sow and grow hollyhocks

Hollyhocks no longer quite fit their let-them-get-on-with-it cottage garden image. But if you give them care and attention, they are worth it come July. With their open, saucer flowers, splashed all the way up their jack-and-the-bean-stalk stems, each one busy with butterflies and bumblebees, they'll more than repay your efforts.

Sowing and growing instructions

1. Fill a tray with compost and water it well to ensure that it is consistently moist. If you water after sowing, you can wash the seeds about and bunch them together – not what you want.

2. Sow the large seeds individually, spacing about an inch apart on the compost surface, in a grid. Don't push in the seed, as you then won't be able to see each one. If you are distracted, it's all too easy to forget where you've sown and where seeds still need to go. Left on the top, they are clearly visible. When the tray is full, cover lightly with compost.

3. Spaced widely, the seeds can germinate and grow on for a few weeks before you prick them out. This saves you time in the end, rather than simply chucking seed about willy-nilly.

4. Place the tray in a warm and cosy spot to germinate. You don't need light at this stage. I cover seed trays with an empty compost bag – opened out – to keep in warmth and moisture and speed germination. If you do this, after about a week, check trays every morning and night for germination. Once this starts, remove the light-excluding plastic.

5. Hollyhocks take 10-14 days to germinate and then another 3-4 weeks before they're ready for pricking out. If roots are showing at the base of the tray, they're ready to move on.

6. To prick out, handle only the seed leaves, not the stem (which bruises very easily). Get a pencil (or stiff plant label) right under each plant and try to tease out every individual seedling, roots and all.

7. Place each seedling into its own pot of peat-free compost, firm down and water.

8. The ideal spot for growing on has maximum all-round light – ideally, plants should have warm roots but cool tops.

9. Hollyhocks will be ready for planting out in the garden by June, but won't flower well until the following year.

10. You might get the odd plant trying to flower sooner, but snip off the flower spike. This helps the roots to get established before the demands of flowering begin – otherwise you'll have even more trouble with rust.

Rust remedies

I always think of hollyhocks as archetypal cottage garden plants (you often see them growing beautifully in churchyards). The cleaner, sulphur-free air that we all now enjoy, however, means that fungus on roses and hollyhocks is more common. Both plants need tinkering to be at their best.

Rust fungus forms little pustules on the underside of hollyhock basal leaves and often spreads from there up the stem. As Rosanna says, if you want to grow your hollyhocks right by a path, as she does, they need to look vigorous and healthy. The only way to guarantee this is to use fungicides. Bordeaux mixture, a traditional copper sulphate-derived remedy, is not enough to hold rust at bay, you may need to use stronger fungicides...

 

If this all feels far too much like chemical warfare, ignore any rust problems and hide the foliage of your hollyhocks by putting them nearer the back of the border.

 

Make more plants

Hollyhocks self-sow, so once you have introduced them they should spring up of their own volition, but they will creep to the sunny, open front of the bed. Watch out for this and dig some up and put them further back out of the limelight to get a balanced sweep. Don't transfer them directly, though – they need a short spell of TLC.

 

Dig up self-sown seedlings and pot them into a 3in pot. Once the roots have filled it, move them on into a slim, deep pot to accommodate the tap root. At Sleightholmedale in Yorkshire where there is a wonderful Hollyhock display, plants are grown on until they're well established before being planted out towards the back of the border.