It’s September, and it’s another busy month in the garden.

by Ken C | Last Updated: 01/09/2021

Well, the children will soon be back to school, and I hope you managed to have a short break away. Or maybe your holiday was being at home and using the garden. Whatever you decided to do, the weather this year had played some dreadful tricks on us all with a beautiful start, a rotten middle, and who can tell how it will end.

As gardeners though, we always grumble whatever is thrown at us. Too cold, too wet, too hot, too windy the list can go on and on. I just know as a gardener, having been one since leaving school, the weather patterns have definitely changed from when I first started. 

A good year for fruit and flowers

Enough grumbling as this year has produced some great flower displays on everything from those early flowering shrubs to perennials, and vegetables and fruits alike. There’s an abundance of fruit on the late-flowering fruit trees as they missed those frosts, but more about fruit later.

Lucy Chamberlain, who is Head Gardener at East Donyland Hall, has been growing melons amongst many other things. But as the fruits get larger and become heavy, they need support. In our greenhouse, my Dad used to use cut-up onion sacks or my Mum’s old tights strung to the greenhouse supports. We always as used to grow Cantaloupes with their orange flesh, and they’re so juicy when ripe.

The Mirabelle is so plentiful this year, I can’t believe how many are on the trees. Commonly called Cherry Plums they are in fact plums and are grown mainly in Lorraine, France where they are harvested like olives by shaking the trees.

Several gardens I visit have them growing, as do Wilkins and Sons on their farm for jam making. They are like a large cherry, yellow with a fleck of rosy red although some are more yellow and others redder, the flesh is sweet and tender, and when perfectly ripe, soft and jelly-like. Chefs use them for tarts and they make superb jams and jelly.

So if you’re thinking of growing something different, why not check out Pomona Fruits as they have a range of Mirabelle from the traditional Mirabelle de Nancy to a red variety Countess or a yellow called Golden Sphere. It will remind you of your Mediterranean holidays.

Show your Lavender some love

As we go through this month, if you haven’t cut the dead heads off your Lavender then it’s something you really must do. If you don’t, the danger is that second flowers will appear and then you feel guilty cutting those off and the plant will end up leggy as a result.

When pruning Lavender, always cut into the young wood about an inch and this will encourage fresh new growth if not the plant will become woody, and give it a liquid feed like Maxicrop to give it a boost. With a bit of luck, you might still get a second flush of flowers even though quite sparse.

I’m hoping you’ve kept Rhododendron, Azalea, and Camellias well-watered and fed through last month and this. Why you ask? Well this is when the buds are being formed for their flowers, and if they don’t get enough the stem to the bud can’t feed the flower and it browns and drops off and you will be disappointed that when the time comes, your bush doesn’t flower.

Hedges and conifers need pruning

If you have a Laurel hedge or maybe Portuguese Laurel, or even a conifer, it’s worth doing a prune before winter. I’ve just pruned a Laurel hedge and as it was smallish I used as I always would my trusty pair of Felco No 2 a great pair of secateurs that will last you for years. Prune back to just above a leaf and that will produce a shoot from the leaf axil.

Stand back to check the top is level and remember, the tops of hedges are generally level and do not follow the lie of the land!

I have a hedge that’s 60-metres long, and there’s no way that I can cut that with secateurs. Instead, I use a commercial-grade Stihl battery-powered trimmer.

As a professional gardener, it makes sense to use commercial tools but there are domestic ranges as well that are really good.  I’ve previously recommended the VonHaus Cordless Pole Hedge Trimmer from Amazon on one of my YouTube videos, but the Bosch 18v Cordless Pole Hedge Trimmer is getting some rave reviews.

The only problem with using a powered trimmer on a hedge with larger leaves is they do end up getting cut badly. The leaves then go yellow and drop off which can make a mess. When I’m on a job, even when we factor in the time it takes to clear them up, it’s still quicker with a big hedge than doing it with secateurs.

If you have evergreen hedges, including conifers get them trimmed now, and then any small new growth will be hardened by winter. 

Talking of hedges, it is now time to cut back your Beech and Hornbeam hedges – normally late August is best. Then, as the leaves go brown, they should stay on all winter and it will continue to give you a good screen – this is why people plant them as an alternative to evergreen.

Bulbs, bulbs and more bulbs!

I mentioned last month to look out for bulbs as they are now in Garden Centres and Nurseries. 

The best time for Daffodils and Narcissus to be planted was late August but let’s face if we were still waiting for Summer to arrive, perhaps we should give up and get on with Autumn. Still buy bulbs and keep somewhere cool – if not they will lose moisture and deteriorate.  

Daffodils can look great naturalised and especially with more of us having wildflower and natural areas in the garden. You see it in books and magazines and on TV programs – people broadcasting their bulbs onto these wild areas and then planting where they land.  That’s arduous and it will take you ages.

My advice is to grab your spade, dig a hole, pull back the turf or grass, and pop in between five and nine bulbs. Pop the turf back, and push it in with your foot. Remember to stagger the holes, and never plant in lines. That’s it, job done. 

Tulips come in a huge range – dwarf, frilly, early and late flowering, and even wild varieties. So where to start?

What about buying online as I do at “Direct Bulbs“ – their range of Tulips is fantastic and this month is when I start planting them.

I was once asked by a BBC Essex listener who rang my Saturday Gardening Show, they’d found our number and I was only too pleased to help, and they wanted to know how to treat Tulips after flowering because they got fed up with only getting one season out of them.

Here is the answer I gave – it’s what I do, and it works!

Plant the Tulips, early and plant them 10” / 25 cms deep.  That’s not, and people will think you are crackers. But when I first did it, the bed was clear of summer bedding and once the bulbs were in, I lightly cultivated the ground and planted some wallflowers in the bed above the bulbs.  If you want something different, you could plant, Winter Pansy, Viola, Forget Me Knot, or Bellis Perenniis. Job done.

Up come the Tulips, and they poke through the plants to give a sensational show. Then, as they fade, cut the dead heads off and wait for the leaves to yellow, allowing a bit of goodness to go back into the bulb, and then remove the leaves and plant some summer bedding on top of them.

The first time I did it, I had those Tulips flowering in great condition for nearly five years, so try this method and increase the longevity of your Tulip bulbs.

Plant some vegetables ready for next year

Talking of planting bulbs, it is the best time to plant overwintering Onion sets, a good one to grow is Senshyu Yellow a Japanese variety. If planted around the 15th of this month, you could be harvesting them next June! And if you like red onions, why not try Red Electric which will be ready for harvesting in July next year.

It’s not too late in Southern parts of the Country to sow some Winter Density lettuce, some radish, and maybe some turnip – which should, in my opinion, be pulled when golf ball size!  Last but not least keen vegetable men like Andrew Tokely of Kings Seeds, always suggest sowing Green Manure this time of year. They germinate quickly and are dug into the plot as manure – just what it is called eh!

Most people I know haven’t enough room in their veg plot to do this and to be honest it’s not something, I do but it does help add nutrients back into the soil ready for the next growing season.

Keep up the watering…

Don’t forget, if it stays dry (!) you need to keep watering your crops as they can keep growing well into the Autumn if the weather stays warm enough.

If you have any gardening-related questions or if there’s anything you’d like me to cover on my blog or my YouTube channel, then please let me know.

Happy gardening!

Ken Crowther is an award winning broadcaster, author and member of the Chartered Institute of Horticulture. He has been gardening for over 50 years and his knowledge and experience are drawn on to provide advice and information about garden design, plants for all seasons, gardening techniques and gardening tips. Gardening with Ken's broad appeal means he reaches a wide audience across the UK from amateur gardeners to top level horticulturists.