What to Do in the Garden This Week - August 21st

Published on August 21st 2020
Echinacea daisies and sea holly in a garden
This week, I've some tips on plant care if you're lucky enough to be away, some propagation ideas and some planning ahead for winter planting, including priority planting of some great bulbs. But make sure whatever you get up to in the garden, enjoy it!
For more information check out my full monthly guides:

Watering and holidays

house or indoor plants
  • Indoor plants will survive your absence if they have enough water. Putting them in the bath on top of an old wetted towel may also be enough. Placing them on a draining board covered by capillary matting -with the ends in a partially filled sink- works well too.
  • It may seem obvious, but this is the time of the year that saucers under pots help to stop plants drying out by increasing the water holding capacity.
  • Ask a neighbour, friend or relative to water your plants for you while you're away. Encourage them to take vegetables and fruits that otherwise would go to waste.
  • Moving plants to the shady side of your home will help reduce water demand.
A Hosta plant in a pot


Silver leaf disease on plum shoots
  • Sow seeds of autumn onion (sometimes called Japanese onion) this month to give you the earliest crop of next year. You’ll be able to buy onion sets of these next month, but seeds are cheaper!
Onion seedlings in a garden
  • Regularly pick runner beans, French beans and courgettes. If you don’t, they will stop producing. These can be used to make excellent chutney or can you can give them to neighbours and friends.
  • Harvest all marrows and cucumbers regularly. If you don’t, they will also stop producing. Give excess away or conserve them. It's even better to throw excess on the compost heap rather than leave them on the plants!
  • Remove lower leaves if they show signs of powdery mildew. Try spraying with a mix of 50:50 milk and water. Let me know if it works for you too!
Powdery mildew on marrows
  • Make sure to provide tomatoes, sweet peppers, melons, chillies and aubergines with high potash liquid feed.
  • Remove lower leaves from tomato plants when they start to show signs of going yellow. Removing them too soon can lead to uneven fruit ripening.
  • Keep watering tomatoes evenly. If it varies too much, your fruits may get dead black tissue at the bottom end called ‘blossom end rot’.
Red tomatoes sitting on a table

Flowers and ornamental plants

  • Trim lavender as the colour fades from the flowers. Remove just a little bit of the shoot too, as this will encourage branching out. If plants have become straggly, delay harder pruning until late spring.
  • If you want to dry lavender, then you need to harvest the flowers before the colour fades. Hang them upside down in a cool, dry and airy place.
Harvesting lavender at Babylonstoren
  • You can take semi-ripe cuttings of many plants now. These are cuttings that have a slightly hardened and woody lower end and will root best on a mist bench. It's surprising what will root in a pot of compost covered with a thin polythene bag.
  • Get catalogues as they become available and order ornamental trees for winter planting. These will normally be delivered in mid-winter.
  • Plant snowdrop bulbs and anemone corms just as soon as you can. They can be challenging to get going, but by planting early, they can establish much more readily. The longer they are out of the ground, the more dormant they become and challenging to re-awaken.
  • Autumn flowering crocus should be planted as soon as possible as they will flower this October. They bloom before the leaves appear and this has earned them the common name ‘naked ladies’.
pink autumn crocus flowers
  • Hyacinths prepared for forced flowering around Christmas will be coming out of temperature treatment now. Get potting them up for some inexpensive scented decorations for Christmas!
  • Plant Nerine bulbs in a position where they get plenty of sun and where the soil dries quickly. By a wall or hedge works well.
pink Nerine flowers against a wall
Free download for your phone or tablet
Download on the App StoreGet it on Google Play

Lots to see

Follow and read AlanGardenMaster’s articles as he develops his new one-acre plot. PimlicoDan shows city gardening in a whole new light, or follow DaisyDays on her adventures in the allotment and as a professional gardener. Just a few of the many personalities you’ll meet in our app. Free download for your phone or tablet.
Download on the App StoreGet it on Google Play


Subscribe for the latest updates from Candide

What is Candide?

Candide has everything for plant lovers – buy plants from independent sellers and book tickets to visit inspiring gardens near you. Identify plants in seconds from a single photo and learn how to care for them with our in-depth guides.


Learn how to care for your plants and share your growing successes on Candide’s free app for your phone or tablet.

Download on the App StoreGet it on Google Play

Germinated in Bristol © 2021 Candide