What To Grow In September – Our Expert Guide

As the media gets excited about a potential fifth heatwave in September, many of us are looking at our parched gardens and wishing that we could wipe the slate clean and start again with some fresh plants and renewed colour. The beauty of nature is that, to a certain extent, you can do just that. September is a great month to get ahead, with both flowers and winter vegetables, many of which will be harvestable this side of Christmas. Rosebie Morton, founder of The Real Flower Company, shares her top tips on what to plant in September.

Rosebie Morton’s September Gardening Guide 2026

Salad Leaves

I have found vegetables this summer challenging to say the least; my cut and come again lettuce barely germinated and then got crucified in the heat. Even my courgettes, normally so reliable, have been a failure. But let’s forget the failures, move on, and plant things like hardy winter spinach. Sown in a shallow drill, lightly covered and kept moist, it will produce leaves in a few weeks which can then be harvested for baby salad. Or leave to mature and harvest later in the winter (in hard frosts it is worth protecting with fleece). 

Equally worth growing are salad leaves such as mustard, mizuna, lambs’ lettuce and rocket. The latter I had huge success with by sowing it in the autumn and then harvesting it all through the spring. Sowing it now means that it doesn’t bolt as so many vegetables do around early summer when they are intent on setting seed.

Veggies

There is no faster-growing salad crop to reward you than radishes. Providing a delicious crunch in a matter of a few weeks. Another firm favourite to sow now is broad beans, which are quick to establish, even before the temperature drops. They can then sit dormant over winter and get going again in the spring. They produce tender tiny beans in late spring, but don’t sow them until late September; otherwise, they will get too tall.

Onion sets are also a good choice for planting now into well-prepared ground, with their noses just peeping out of the soil. Garlic sets, likewise, can be started now and will happily see out the winter and get growing in the spring.  

Spring Bulbs

If vegetables are not your thing, then think bulbs and spring colour. Many bulbs can be planted now either direct into borders or pots. The advantage of early planting is that the soil is still warm so the roots can establish themselves before winter, but avoid planting tulips until November to lower the risk of the fungal disease known as tulip fire. 

Snowdrops are one of the easiest bulbs, in that they will grow anywhere, and are the first bulbs to flower. Often a welcome sight as early as January and planted with Aconites, together they make a wonderful combination of white and yellow. The latter are a bit fussier; they like winter sun but don’t like summer heat, so plant them under deciduous trees and shrubs.  

Iris Reticulata brings an exotic touch to the front of beds, or it can be planted in clumps in pots. They come in shades of blue and purple and are a fantastic early source of food for bees. On that note, Crocus are also a wonderful flower for providing pollen and nectar to emerging hibernating insects and offer a serious blast of colour to grey days. 

Obviously, daffodils are a popular choice, and rightly so, as are Muscari and English bluebells for woody areas. Stay clear of the Spanish ones, which pose a threat to our native English flowers. Finally, don’t forget Alliums; planted now, they will bridge the gap between spring and summer.  

So, let’s forget heat waves and embrace September with fresh eyes and promising crops.