If deadheading your rhododendrons has got away on you, at least do those which set seed. Some set so much seed that it can weaken the plant and kill it. The seed setters will usually show open seed pods from last year still hanging on looking like little wooden stars and they show no growth from that spent flower tip. These types of plants can tend to be leggy and spindly – they are putting so much energy into reproducing themselves that they forget to grow. At least try and deadhead these ones. It is not so critical to deadhead varieties which set very little seed although they do look better for your efforts.
If you have water features, try and prevent invasive water weeds getting away on you. We have problems with water hawthorn in our stream which we extract with a rake head on the end of a long pole. Over the years, Mark has eliminated the unwanted oxygen weed (fine in fish tanks but not in waterways). And some of the water lilies can be so invasive that they cover all the water, which is a bit self defeating for a water feature. Best to get rid of the rampant ones and replace with better behaved varieties. Or thin the plant back to one crown.
As the yellow primula heladoxa finishes flowering, deadhead it to prevent it spreading seed. This is another plant with weed potential and as it usually grown alongside water, it can spread some distance if it is a stream.
Annuals such as asters, zinnias, snapdragons, stocks and Iceland poppies can still be started from seed and will give you good flowering in late summer and autumn.
A bit of a typo last week when we advocated continuing successional sowing of broad beans. That should have been dwarf beans.
Now is the important time to start getting winter vegetables into the ground, such as Brussels sprouts, celery and leeks. The seed of these will have been started some time ago to get good sized plants for you to plant out. If you want to do leeks from seed yourself, this is about as late as you leave it. Sow the seeds in situ immediately. They won’t get as large as the seedling plants but you should still be able to get a crop through.
Mulch and feed asparagus beds. They are gross feeders. Compost and animal manure are ideal.
Thin apple crops if it looks as if too much fruit has set. More is not better. Trees can overcrop and quality suffers. Shorten the spurs on apples and other fruit trees such as plums and kiwifruit. In other words prune back to two or three leaves on new growth. This encourages the formation of flower buds and fruit for next season. It is the same with wisterias, as mentioned last week.