Alan's Monthly Garden Calendar - August; Ornamental Garden Tips

AlanGardenMaster
Published on August 11th 2019
36
A close up of Dahlia flowers

August is holiday time but also a time to propagate plants. The first new batch of bulbs will arrive in garden centres, and I've highlighted those that will need urgent planting. I also have some tips on flower bulbs and lawns, and be sure to check my weekly garden tips for even more memory joggers!

Propagation

  • Some hardy annuals can still be sown now. Californian poppies [Escholscholzia] are so easy to grow and should be sown directly into a well-prepared seedbed in full sun where they are to flower. Poached egg plants [Limnanthes] are an excellent choice for bees. Larkspur, Clarkia and Godetia are all easily grown from seed and will flower well next late spring and summer.
A close up of a clarkia flowers
  • Sow biennial flowers now too. Brompton stocks, forget-me-nots and sweet Williams are old favourites that are best sown in a row and transplanted to the flower border in autumn. They will provide masses of inexpensive colour in spring and early summer next year.
  • Take cuttings of fuchsias, pelargoniums and other tender plants. To pot, use a half and half mix of vermiculite - or perlite - and compost, and dip the cut ends in fresh hormone rooting powder. Cover the top with a thin clear polythene bag (leave Pelargonium uncovered). Select healthy shoot tips [preferably without flowers] and root them on your windowsill.
  • Propagate some succulents by taking leaf cuttings. Carefully remove leaves from Graptopetalum, Graptosedum, Graptoveria, Echeveria or Sedum plants and lay them on top of a pot filled with a 50:50 mix of potting compost and perlite/coarse grit. Spray them over with water every now and then, and soon they should produce roots even though they are just lying on the surface. Pot them into individual pots and grow them on!
Echeveria plants
  • Propagate succulent plants that root from stem cuttings. Try this on Aeoniums by cutting a side shoot off and inserting the end in a 50:50 mix of potting compost and perlite or coarse grit.

Bulbs

  • The first spring-flowering bulbs will be in shops soon. It’s vital to plant snowdrops and autumn flowering crocus immediately. It’s good to plant daffodils and Narcissi as soon as possible as they soon start to regrow.
Children planting bulbs in the grass
  • Plant snowdrop bulbs and anemone corms just as soon as you can. They can be challenging to get going, but planting this early means that they can get established much more readily. The longer they are out of the ground, the more dormant and difficult to re-awaken they become.
  • Autumn flowering crocus, Colchicum and Saffron crocus should be planted as soon as possible as they will flower this October. The flowers will appear before the leaves.
  • My experience is that Narcissi and daffodils make better plants if planted this early because they start to form new roots straight away. So plant them as soon as you buy them!
  • Hyacinths prepared for forcing and flowering around Christmas will be coming out of temperature treatment at the end of August. Get ready to pot up some for inexpensive scented Christmas decorations!

Shrubs and border plants

  • Watch Fuchsia for gall mite. Promptly pick off infested shoots and burn them.
Fuchsia gall mite damage
  • Check Viburnum for leaf beetle. This is widespread in public shrub planting, and Laurustinus are especially prone.
  • Watch Clematis, roses and honeysuckle for powdery mildew. Roseclear fungicide sprays may control this but remove the worst affected parts of the plant first. Try 50:50 milk and water spray in full sun if you prefer non-chemical means. Water the roots of affected plants too.
  • Make sure that recently planted trees, shrubs and climbing plants are given a good soak. They will have a limited root system and could suffer from a lack of water this month.
  • This week may be a good time to control vine weevil by using a biological predator - nematodes. These are simple to water onto pots and borders but make sure that they are wet and you have agitated the solution before you apply it.

Ponds and bog plants

  • Thin out oxygenating weeds, floating plants and plants that are growing on pond margins. Aim to have no more than half the water covered by plants. Remove no more than this as fish and other pond wildlife need the shade and shelter that these plants provide. Try to take out the dead leaves of plants such as water lilies to avoid them rotting at the bottom of the pond.
  • Top up the pond water level if it gets low. Make sure that the lining is covered to lengthen its life.
A garden pond with low water level
  • Add Agralan Citrox to water features to keep the water clean. Incidentally, this can also be used to clean pots, trays, glass, benches and pruning tools!
  • Remove dead leaves and flowers from the water. When they rot, they can release toxic gases.
  • With small children around, cover ponds to keep them safe from accidents.
  • Regularly remove duckweed and blanket weed.
  • A pumped fountain or small waterfall will introduce more air into the water.
A garden water fountain

Lawns

  • If floppy plants make cutting lawns close to the borders difficult, it could be worth laying a line of decorative paving for them to lie on top of. You also can buy very effective plant supports.
  • Check lawns for chafer grub damage. Look for yellowing patches that, if pulled gently, will come away easily with little or no roots. Sometimes the first sign of chafer grubs will be holes made by magpies, jackdaws and badgers. You can control this pest using specific natural predators.
A bowl of chafer grubs
  • Cut the lawn edges regularly. Now may also be a good time to use an edging iron to straighten them out. The insertion of a plastic or metal edging strip will support the edges.
  • Let the grass on your lawn grow longer. This is not an excuse to mothball the mower until next spring, but rather a good ploy to get through dry periods without having to use as much water to keep the lawn looking green. Raise the mower blades to about two inches and reduce cutting frequency.
  • Grass looking brown? Don't worry, because even if you don't water your lawn, it usually bounces back and becomes green again as soon as the autumn rains arrive.
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