Roehampton Garden Society

Watering plants and conserving water

Water, precious water

We are entering a possible drought situation so we all need to do what we can to avoid wasting water. Also it is part of our ethos of being environmentally responsible to conserve water as much as possible.

A few tips on how we can help use less water:

  • Do not use a sprinkler. So much of the water evaporates and it is against RGS rules (Rule 22)
  • Water the ground as near to your plants as possible. This also helps with weed control as you won’t be watering the weeds as well as your plants.
  • Watering under the top growth of your plants will help to reduce water evaporation as it will tend to be cooler and will create a humid environment.
  • Can be good to have a watering hole next to larger, water hungry plants like tomatoes and the cucurbit family of plants (courgettes, cucumber, pumpkin, squashes etc). An upside down plastic bottles with the bottom removed works well – see photo. Water into the bottle. Not only does this mean water goes to the plants’ roots it also means you are not watering the weeds.
  • Ensure you have good seals in your hose pipe system. The brass tap attachments are usually better than the all plastic ones.
  • Try to avoid watering in the heat of the day. Best to water either early in the morning or as late as possible in the evening.

Alone we won’t prevent a hose pipe ban but at least we will be doing our environmental best.

with thanks to Helen Finch.

And for even more good watering advice – see the RHS website

August jobs on your allotment

Maintaining soil structures and planning ahead

  • Green manures such as Mustard and Phacelia and Grazing Rye can be sown now.
  • Continue regular weeding to avoid build-up of work later.

Sowing and Growing

  • Sow oriental vegetables such as mizuna, pak choi and mustard greens for salad leaves- they bolt less at this time of year.
  • Sow parsley to last through till spring on a sunny windowsill.
  • Sow Swiss chard and perpetual spinach at the beginning of the month.
  • Make a last sowing of beetroot at the beginning of the month.
  • Sow fast-growing ‘catch crops’ for autumn use, such as radish, lettuce, rocket and turnips.
  • Plant out winter brassicas, broccoli, kale and cabbbages in soil which has been limed at least 6 weeks before, to reduce club root infestations.
  • Plant new strawberries now, either as detached runners or new plants.
  • In dry weather keep runner beans well-watered twice a week to aid setting.
  • To reduce risk of tomato blight, water directly onto the roots not the leaves.
  • Feed courgette plants weekly with a high potash liquid feed to continue fruiting.
  • Summer prune trained fruit trees such as fans, espaliers and cordons.
  • Prune plum and damson trees after fruiting. On grape vines shorten fruit bearing branches to two leaves beyond the fruit bunch.
  • Prune out fruited canes of summer raspberries.
  • Tie in new canes on raspberries and blackberries.
  • On grape vines shorten fruit bearing branches to two leaves beyond the fruit bunch.
  • Cut back chives if showing signs of rust and new shoots will quickly appear. Remove mint plants showing signs of rust. The disease will persist over winter and re-infect new plants next year.
  • Pick off and destroy rosemary leaf beetle which are active at this time of year.
  • In the greenhouse avoid splashing water onto leaves. Moisture triggers spore germination of fungal diseases.


  • Harvest sweet corn when a grain exudes milky juice when tested with a fingernail and the whiskers are brown.
  • Harvest onions and shallots when the stems are dry and papery.
  • Start harvesting runner beans, parsnips and cucumbers when ready.
  • Complete harvesting of second early potatoes and begin to harvest main crop potatoes as they begin to flower.
  • Harvest early ripening apples and pears.
  • Harvest carrots, but leave protective insect mesh on carrots until autumn.

Gardening for wildlife

  • Leave some flower seed heads on plants as source of food for wildlife.
  • Cut and shake ripe seed heads of annuals over suitable patches of bare soil for flowers next year.