August 15
As the days grow shorter and there is dew in the early morning, powdery mildew is appearing on leaves of squash, etc. It is a fungal disease and widespread on vegetable and many ornamental plants as humidity at night increases. It is part of the growth cycle on the coast and a sign the plants are slowing down and fall is coming. Good air circulation helps keep it at bay. There is nothing much to be done. You can remove the leaves if you like but you are removing some photosynthetic tissue or you can spray with sulphur which is acceptable for most organic gardening practices or leave it alone.

Check the underside of your leaves for pests. I saw some gray aphids on the underside of brassicas today. Control them while the colonies are small. Hose off the underside of the leaves or wipe off with a soapy cloth. The aphids will not kill the plant but the leaves become distorted and growth is slowed.

We generally get a second hatching of carrot rust fly late August and September. Keep an eye on your carrots and harvest as soon as you find an infected one or, cover with Remay floating cover and seal the edges to the soil. Any carrots that have brown tunnels in them should not go into the compost as the maggots will complete their life cycle there and hatch out in the spring. You can still eat the carrot if you cut out the tunnels and destroy any small white worms you see.

Some weeds seem to be growing very happily around the place. Weeds generally produce large numbers of seed or have underground runners and can spread themselves around easily. Get rid of them now both from the beds and paths. Mulching certainly helps to keep weeds down as the seeds often need light to germinate.

Harvest beans every couple of days to keep the plants producing. Once a plant has reproduced itself, it has passed its genes onto the next generation and therefore can stop growing and flowering. It has completed its lifecycle.

Winter vegetable starts should be appearing in the nurseries in a couple of weeks or so. Keep yours eyes open for them if you haven’t grown your own.

Water less as plants are slowing down and there is little soft growth. The exception to this is any seeds you may be starting although the dew we are getting now does mean they will not need as much water as plants started in June. Dig down at least 15 cm and check the soil moisture before you water. I think you will be surprised.