July Gardening Tips – from Strelitzia Garden Design

Cut Back Perennials

The scruffy foliage of perennials that flowered in May and June, but have now finished, can in some cases be cut right back to ground level. They will respond by producing a new flush of fresh leaves and, if you’re lucky, more flowers too. This works for the oriental, perennial poppies, delphiniums, lupins, anchusa, and many geraniums (the hardy, true geraniums such as ‘Johnson’s Blue’, rather than pelargoniums, which are also, confusingly, known as geraniums).


This crazy weather means watering is difficult to keep on top of. Our temperate-climate plants didn’t evolve to deal with this level of heat and dry. I’ve got four water butts, but they’re all empty now. Moving plants in pots to shadier positions, and making sure they have trays under them, can help reduce drying out.

And if you can find the time, why not write to the government to remind them we need to stop burning fossil fuels, and asking them to start subsidising renewable energy, rather than oil, gas and coal?

Prune shrubs

Shrubs like Deutzia, which have flowered, can be pruned now. Cut out the flowered shoots. Next years flowers will be produced on the new shoots. Mature plants may need thinning out and reducing in size. The way to do this is to cut about a third of the oldest stems back to ground level. By doing this every year, the plant is being constantly renewed on a three year cycle (and may even live forever!)

Prune Cherry and plum trees

…which are susceptible to silver-leaf disease. The spores get in through damaged (or cut) branches, and are most prevalent in the cold, damp part of the year: so mid-summer is the safest time to prune. This holds true for ornamental trees, as well as those grown to produce fruit.


If you’ve got a wisteria that’s throwing out lots of long, wayward shoots, you can cut them back to around 30cm from their origin. In late winter/early spring they should be cut back to a few inches, or to a couple of buds.


If you want to increase your stock of plants, keep taking cuttings. Cuttings from some plants root so easily you just need to pop them into a jar of water on a windowsill and roots will appear within days.  A good example is salvia (sage), including the popular salvia ‘Amistad’. From one plant bought earlier this year I’ve taken ten cuttings, and quickly produced ten new plants!

On-going jobs

  • Keep on dead-heading roses, dahlias and day-lilies, etc.
  • Keep feeding potted plants on a weekly basis
  • Keep on top of the weeds
  • The hot, dry weather means that grass isn’t growing. In fact, it’s mostly going brown (don’t worry – it will soon green up once the weather changes). Try to resist the urge to use valuable water on the lawn – just be glad of the time you’re saving by not having to get out the mower!

And lastly…

We don’t often get weather like this in our mostly cold little island, so make sure you enjoy the sunshine while it lasts.