Late Summer Jobs in the Flower Garden

Jobs to do

Preparing the soil for sowing outdoors

If you would like to have annual flowers in bloom in late spring and early summer next year, early autumn is the time to sow them and you should therefore prepare the soil during the next few weeks. As they will flower where sown, you should choose a site which is reasonably sheltered from wind and cold, so that they survive the winter. Fork the soil to the depth of the tines and mix in an average-to-light dressing of organic matter, depending on whether the soil is mainly clay or sand, and remove all weeds and large stones as you go.

The site that has been left fallow for sowing a lawn in early autumn can now have lime mixed into it, if the soil is too acid, to bring it up to a pH of about 6.0-6.5. You can take the opportunity at the same time to break the soil up into a reasonably smooth texture, levelling it as you go and cleaning it of weeds and stones.

Preparing the soil for planting outdoors

There is little to do here; the same plants as were planted late in mid-summer can still be put in, so soil preparation will be as for that season.

Preparing compost for sowing seed and potting You will need compost for both these jobs; the potting will include all sizes of plants and bulbs for Christmas flowering, which will do perfectly well in standard composts.

Planting outdoors

The plants to go in in late summer are the autumn-flowering bulbs but they should be planted as soon as possible, otherwise you will find that they are starting to sprout before being put into the ground. They include colchicum, autumn-flowering crocus, Nerine homdenii and, although a few weeks earlier than other lilies, you can plant the Madonna lily Lilium candidum. It should be planted so that the bulb is only just covered with soil, preferably sitting on some silver sand, with a little more sand mixed into the soil round it. As with all lilies, be careful not to damage the fleshy roots. It will do best in slightly alkaline soil and a sunny place, though shade will not come amiss.

Sowing seed under glass

campanula isophylla

Seed of schizanthus and cyclamen can be sown in pans or seed trays filled with a standard seed compost. Schizanthus seed sown now, for flowering in spring, should be well spaced out; it is important that the seedlings do not become drawn at any time, otherwise the adult plants will be leggy and will flower badly. The containers can be put in a frame outdoors, as schizanthus do not need great warmth for germination, but they should be covered until the seedlings do appear

Cyclamen should also be well spaced out, lightly covered with sieved compost and given a further covering of black plastic or glass and paper until they germinate. Keep the containers in the greenhouse; when sprouting starts, take off the coverings and put the seedlings in a shaded place, with a warm, even temperature. They will take several weeks to germinate and some seeds may take much longer.


Although it seems unnaturally early to be thinking about it, flowering plants at Christmas will only be obtained if you start potting them now. Towards the end of late summer it should be possible to buy bulbs, such as hyacinths, daffodils and narcissus, specially prepared for early flowering. You will get good results with these and be able to keep them for future flowering if you pot them in a good, standard compost rather than bulb fibre, which contains practically no nourishment.

Hyacinth bulbs are large, so one will be plenty for a 12.5cm (5in) pot; two narcissus or daffodil bulbs, with offsets, will be enough for the same size pot. You can put more into this size pot but it gets so crowded with roots that they come out of the drainage hole and up onto the compost surface. All these bulbs should be planted with the ‘nose’ (tip) of the bulb above the surface of the compost; don’t make the compost too firm beneath the bulb and don’t press the bulb down hard, otherwise the roots grow upwards rather than downwards.

After potting, put them in a cool place with a temperature no higher than 7°C (45°F), in complete darkness, and leave for about ten weeks, checking occasionally to see if they need water.

You can also pot the miniature iris, I. reticulata, for flowering early in mid-winter; use a compost slightly on the sandy side and cover the bulbs to their own depth, putting five in a 12.5cm (5in) pot. Lachenalias for mid-winter flowering can be planted in the same way now and both these and the iris can go into a cold frame until late autumn; water them occasionally if need be.

If cyclamen were slow to start in mid-summer, they can be potted now; the timing of various jobs with plants is never exact because it is dependent on the weather and can vary each way in every season. Nor is it too late to pot frcesia corms; they will merely flower a few weeks later than if potted in mid-summer.

Calceolarias, cinerarias and primulas (malacoides, obconica, sinensis and stellata) sown in early summer, will now need moving into 7.5-10cm (3-4in) pots; those sown in late spring (cinerarias and Primula malacoides) will need moving into 10-12.5cm (4-5in) pots. Fuchsia cuttings from the spring will need 12.5-15cm (5-6in) pots, if they have not already been moved and regal pelargonium cuttings, taken in mid-summer, will have rooted and need individual pots sometime during the next few weeks. The size of the first pot will be about 7.5cm (3in) but if they grew sufficiently fast to need potting at the end of mid-summer, they may be ready for a second move into 11cm (4-1/2in) pots by the end of late summer.

The carnation layers which were prepared in midsummer should have rooted well by now and can be cut from the parent plant, carefully dug out of the soil and put into pots in a cold frame for the winter.


Pansies can be removed to a nursery bed in the shade as soon as they are large enough to handle; lift them with great care and set them so that the leaves are only just above the surface of the soil. Doing this ensures short bushy plants, instead of straggly ones which can easily be beaten down by the rain.

more on Flower Garden Tasks in Late Summer …

29. August 2011 by admin
Categories: Flower Garden, Types of Gardens | Tags: , | Comments Off on Late Summer Jobs in the Flower Garden


Get every new post delivered to your Inbox

Join other followers: