August is a time when expensive plants can easily be lost. What can be done to save plants and shrubs that were so difficult to obtain or grow from seed? Here are ways to avoid losing those rare specimens. And tips on how to make more of plants that you treasure because they were gifts.

Rules for general summer care

• Remember to water every morning, or - if that’s not possible - every evening.
  
  
• Deadhead plants that flower prolifically – geraniums, roses, pansies all benefit from having their blooms removed as soon as they fade. A second crop of flowers often follows.
  
  
• Spray roses for black spot and fungal diseases only when necessary. Keep diseases in check by pruning at the right time and by regular cultivation – sufficient applications of organic fertiliser definitely help to build up a plant’s stamina. If spraying with Scotts' fungicide RoseClear2 (which must be used up by 31 December 2003) follow directions on the packet carefully. The replacement product RoseClear 3 contains myclobutanil to control black spot and other plant diseases.
  
  
• Keep pests at bay with horticultural soft-soap and products such as Nature’s Answer Natural Pest Control. The RoseClear brands serve as pesticides as well as fungicides. RoseClear 2 contains pirimicarb, whereas in RoseClear 3 the replacement bithenthrin is the insecticide.
  
  
• Vine Weevil beetles can be sought and found by torchlight, when they come out of hiding at night, or consider using biological control methods.
  
  
• Bio Slug Mini-Pellets with Animal Repellent is one of the products that has been passed for use under the British and European review of pesticides.
  
  
• Propagate from plants while they are still healthy, to create replacements. This is the fun side of gardening. Making free new plants from choice specimens that were expensive to purchase seems to appeal to most gardeners.

Increase lavender and save the shrub

Lavender is almost always liked by visitors to the garden. July and August are months when it is easy to increase Lavendula augustifolia and other lavenders, by taking stem-cuttings. Guests usually comment on the more uncommon varieties, such as the grey-leafed L.x ‘Sawyers’, or L.a.‘Hidcote Pink’.

Neatly potted up rooted cuttings make welcome gifts. It is a simple task to take semi-ripe side shoots. Push the cuttings into pots or trays of a free-draining compost mixture, and then pop them into a cold frame or under a cloche if you have one. A good tip is to root more cuttings than you actually require, as a few of the stems might not survive. Friends, schools and charities are usually pleased to receive any surplus plants and shrubs.

Lavender has a habit of suddenly ageing. The best way of making sure fresh young specimens are always in your garden is to grow replacements. Renew plants regularly by taking cuttings and sowing seed every year. Seed of the species can be sown in autumn e.g. L. augustifolia, L. stoechas, L.viridis, etc. And now is a good time to order or buy seed.

New lavenders

Unusual varieties in the L. stoechas section are L. ‘Helmsdale’, L. ‘Kew Red’, ‘L.Marshwood’, and ‘Willow Vale’.

‘Walberton’s Silver Edge’ is a new-ish variety of L.augustifolia x intermedia - useful for making low hedges, due to the decorative foliage.

New plants from leaves

Young plants can also be raised from cuttings of conservatory favourites: e.g. take whole-leaf cuttings from saintpaulia (African violet), or section-of-leaf cuttings from plants such as streptocarpus (Cape Primrose). Streptocarpus ‘Paula’ is a variety that grows well for me – the plant is reasonably compact and the flower colour is a pleasing shade of purple.

Propagate from varieties of streptocarpus by taking sections of the long leaves. Insert the cut edges into moist, free-draining compost. Little plantlets develop along the veins of the cut edges. Plants will also thrive and flower all summer on a light windowsill.

New streptocarpus varieties from Dibleys are year-round-flowering ‘Crystal Dawn’, ‘Crystal Charm’ and ‘Crystal Wonder’.