July

General Tasks

  • Deadhead flowers not wanted for seed.
  • Lift and store tulip and hyacinth bulbs.
  • Start tender cyclamen plants into growth.
  • Continue feeding plants.
  • Thin or prick out seedlings of annuals, biennials and perennials sown last month.
  • Sow winter flowering pansies.
  • Check house plants pests.
  • Layer border carnations.
  • Plant late-flowering bulbs.

The Flower Garden in Summer

What to do in the flower garden in July

Watering plants should continue as necessary according to kind. Generally speaking, grey-leaved plants from Mediterranean regions need less water than soft, lush plants such as dahlias.

Keep a look out for wilting leaves, which are a sure sign that a plant needs watering. However, wilting can also be caused by pests feeding off the plants' roots or by certain diseases, so if watering does not perk the plant-up then investigate further.

If you grow plants in window boxes, hanging baskets, tubs, or any other similar container, make sure that they are well looked after. Once in flower and growing well, they will need liquid feeding at least weekly. Watering will be more frequent and should usually be given when the surface of the compost is drying out.

Pruning and Deadheading

Carry on deadheading of flowers not needed for seed production as for May. Deadheading flowers that have a long period of display, such as scabious, gaillardias and achilleas, will ensure they continue producing more flowers. Removing the faded flower spikes of delphiniums and lupins, may encourage them put on a second, smaller display later in the season. Flowers produced on bare stems, such as red hot pokers (Kniphofia) and African lilies (Agapanthus) should be cut right back to the base. Flowers produced on leafy stems, such as peonies and delphiniums, should simply have the flower-head or spike cut off, leaving the leafy growth intact.

Some rockery plants may begin to look a little under the weather this month, straggly and with brown edges appearing on the leaves. Trim them ruthlessly for a fresh display of leaves, and they may even produce more flowers.

Continue feeding sweet peas in bloom, as well as chrysanthemums and dahlias. Check, as you do so, that any supports, in the form of stakes, wire circles or netting, are in good condition and doing their job properly. Continue tying in new growth to the supports, using raffia or soft twine. Make the ties firm enough to prevent the plants from flopping about, but not so tight that growth is constricted.

Lifting and Storing Bulbs

Tulips, hyacinths and other spring flowering bulbs can be dug up in July and stored. Place the bulbs in a single layer in a cool, airy place to dry, and store them in these conditions until planting time in the autumn. You may find that small bulbs have been produced at the base of the larger bulbs. Simply detach these and plant in a nursery bed to grow-on to flowering size.

Tender cyclamen house plants that have been resting after their winter display may start to send out tiny leaves-a sign that they will need potting up in fresh compost. Water well and expose to light and warmth.

Plant autumn flowering bulbs at the end of July for a late seasonal garden display.

What Flower Seeds to Sow in July

Continue to sow any herbaceous plant seeds still remaining. There is still time to build good plants by the winter, but they are very unlikely to flower until next year.

Continue thinning out of perennials and winter flowering seedlings. Biennial seeds sown last month will also need thinning, and you can keep sowing pansies now, ready for winter and next spring.

Any herbaceous and biennial seedlings that are still in their original seed rows, or pots, should be planted out in wider nursery rows soon after they are large enough to handle.

Make a start collecting seeds this month if you want to dry and store your own seeds.

Pests and Diseases

Check houseplants for aphids and whitefly, easily identified by a cloud of white 'flecks' that fly up when you move a plant or inspect it. The leaves of house plants are also vulnerable to red spider mite if conditions are too dry, so spray as necessary.

Outdoors, the usual pests such as backfly and aphids will be troublesome especially on chrysanthemums. Wallflower seedling may also fall prey to flea beetles this month, so treat them sign of trouble.

Various caterpillars will hatching-out now so check the leaves of plants and handpick them off (wearing gloves) or spray with insecticide.

Michaelmas daisies can suffer in July from mildew and fungal rust, which can also infect a wide range of plants, including carnations and pinks. So spray at the first sign of infection, or, if you have had the problem in previous years, spray preventively.

Planting Late Flowering Bulbs

It is now time to look ahead and plan for autumn colour. There are many bulbs that can be plant now that will take over in the borders when the annuals and bedding plants are past their best. Autumn crocus (Colchicum) is an ideal choice.

Taking Cuttings in July

July is an ideal month to propagate hydrangeas from cuttings before the end of the month. After then, many will have formed flower buds in the tops and will be unsuitable. For details visit our Propagation by Cuttings page.

Next page >> Taking care of the Lawn in July >>

Plants for July

Herbaceous perennials in flower this month:

Achillea

Achillea

Agapanthus

Anchusa blue flowers

Anchusa

Astilbe flower

Astilbe

red astrantia flowers

Astrantia (Masterwort)

Campanula flower

Campanula (bell flowers)

Shasta daisy flowers

Chrysanthemum maximum

Delphinium flowers

Delphinium

Dianthus flowers

Dianthus (pinks)

Erigeron pink flowers

Erigeron

Eryngium flowers

Eryngium

hardy geranium

Geraniums (hardy)

Geum

Geum

Helenium

Helenium

Hemerocallis flower

Hemerocallis (day lily)

hosta white flowers

Hosta (plantain lily)

red hot poker

Kniphofia (red hot poker)

Lavatera flower

Lavatera olbia (mallow)

Lysimachia

Lysimachia (loosestrife)

Osteospermum flowers

Osteospermum (cape daisy

Penstemon flower

Penstemon

phlox flower

Phlox

Polygonatum

Polygonatum (knotweed)

Rodgersia pink flower

Rodgersia

Scabiosa

Scabiosa (scabious)

Sisyrinchium yellow flowers

Sisyrinchium

solidago goldenrod

Solidago

Verbascum

Verbascum (mullein)


For bulbs see

Lawns.