Garden Notes for September 2021.
Watering plants is always a good topic of discussion. It is either too dry or it’s too wet. The essential thing is to try to get the right balance. When it is dry the closable leaf pores on plants (technically called ‘stomata’) shut down and slow down the process of photosynthesis. When there is enough water the stomata open, transpiration takes place, allowing the air containing carbon dioxide to go into the plant, which, together with sunlight, powers the reaction of water and carbon dioxide to make the sugars that are the plant’s energy source and building blocks. Watering keeps the stomata open in dry spells. As a rule of thumb one square metre of vegetation draws the equivalent of an inch of rainfall every day. Growth of plants in the summer normally requires additional irrigation. There are now numerous automatic systems that can be put in – especially for containers and hanging baskets.
The start of autumn means that many plants are producing seed heads, which we normally ‘dead head’ to keep the succession of flowers going. At this time it might be worth keeping them. With the cost of seed increasing year on year (the average cost is now around £2 per packet, and can be a lot more) it might be worthwhile considering saving some seed head for sowing. Flowers like Sweet William, Love-in-Mist (Nigella), Cosmos, or vegetables like Runner Beans, can be harvested just before the seed pod has fully dried. Use brown paper bags to hang the seed head upside down and store in a dry place. Remember to label the variety, and then when it is all nice and brown shake out the seed and you have saved yourself pounds for a few minutes work. Unfortunately the lovely hybrids that abound now will not breed true and you will have to rely on the expertise of the professional for that, but if you don’t mind a variety of colour in your Sweet William and so on it is fine.
Whilst the desirable seed heads should be kept, do watch out for all the weeds making sure that they survive. Milk Thistle, Shepherd’s Purse, Plantain and Groundsel- the list is endless, all should be removed before the flower has had time to set seed. I have been having a purge on Shepherd’s Purse that became rampant last year. It seems that no sooner than I have collected another bunch than an equal amount appears on another part of the vegetable garden. In a bit of land where I have a few fruiting trees there has been a huge crop of the weed called ‘henbane’ I have learnt my lesson in the past and have strimmed the area several times to stop the flower heads developing. It may keep them down but there are years of dormant seed just waiting for next spring and it will all start over again.
September is the best month to plant daffodils outside, so make sure you have ordered your new supplies. New varieties are always being offered, like ‘Easter Bonnet’ which has a white perianth and large pink cup. Then there is another one called ‘Petit Four’ which has an unusual cup that opens out into a ball of apricot.
Carrots should be lifted and stored before the roots start to split, which they will do very quickly once the heavy autumnal rains begin. Tomatoes should be cleared from the greenhouse so that it can be prepared for autumn and winter flowers. Onions should be dried and ripened off. In our uncertain weather it is a good idea to put them into a greenhouse or bench where there is plenty of air circulating before tying them up into ropes. Alternatively, use the mesh bags that are used in grocery stores. They need to be kept in the light and to have plenty of air round them, unlike potatoes that need to be stored in thick paper sacks with the light excluded.