September is the time to be thinking of the spring – so flowers like forget-me-not, primulas, polyanthus, Sweet William, viola, pansies and wallflowers should be put into position to give a display when the weather turns mild in March and April. Some people do not like myosotis (Forget-me-nots) because of their habit in seeding wildly all over the place. On the other hand, they are relatively easy to pull up and remove from places where they are not wanted. In addition, they are one of the first flowers to attract pollenating insects. If you had difficulty getting broad beans, or peas this year because of the cold, damp conditions that prevailed in spring, perhaps it might be an idea to sow myosotis near the crop to assist in attracting bees and so on.
Complete the planting of strawberries in September; otherwise they will not have enough time to establish themselves to build up strong fruiting crowns for next year. You can plant them in late autumn or spring but if you want good plants, these later planted ones should not be allowed to fruit in their first season.
Continue disbudding chrysanthemums to leave one bud per stem, otherwise let them go to make a spray of much smaller blooms. Don’t forget to get them in under some protection before the first frosts start from the middle of the month onwards.
Ripen off onions and store them when they are completely dry. Harvest potatoes and keep them in a light proof bag, under cover and store in a frost-free area.
Divide clumps of overgrown perennials and herbs like chives, mint and lemon balm. Cut back marjoram and oregano stems to just above ground level.
Remember to stake tall vegetables such as Brussels sprouts and kale to prevent wind damage later on. Plant spring cabbages before the end of the month
September is the best time to take cuttings of penstemons. The cuttings should be taken from young, non-flowering shoots as these will root readily in a sandy soil kept in a frame. Think about planting bulbs for Christmas display such as the Paperwhite narcisii that I find much easier to grow than prepared hyacinths. Plant them up in pots with bulb fibre in containers that do not have drainage holes. Pack bulbs in closely, and then store them in a cool place under a light proof cover, such as thick black polythene sheeting. They need about two months to develop a good root system before being brought into the light but should then reward you with a wonderful display around Christmas time.
Americans are said to enjoy fried green tomatoes, a delicacy that has not caught on in the UK to my knowledge. Alternatively, why not try ripening green fruit on a windowsill with a banana, which is supposed to help them ripen faster after picking.
Clear away remains of crops that have finished. Order your bulbs, roses, herbaceous plants, shrubs and fruit bushes.
Slightly reduce watering and feeding your house plants. Remember to keep them away from windows as the nights get colder. Reduce the amount of water for cacti. Complete any re-potting and pruning that you may have planned.