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The diary of a cottage gardener - May

Hilary Stevenson of 'The Devon Cottage Gardener' delves into May's to-do list...

Hello May! The rain at the weekend was so welcome for the garden and plants that have been potted on and are now outside in sheltered positions waiting to go in the ground. The soil has been so dry and the need to water had depleted my gathered rain sources, so I was delighted to have my water barrels replenished.

On Sunday I had my first stall at Tavistock Country Garden Show. Of course, it rained all day but that did not deter hardy gardeners from being out. It was lovely to meet people who support buying British flowers and a few who are readers of Launceston Life.

It was fun to share gardening stories, hints and tips and I was a bit overwhelmed by the messages of support in my quest to sustainably grow and supply British flowers. Thank you to everyone who came to say ‘hello.’ There was a great variety of stalls selling amazing plants from all over Devon and Cornwall and I could not resist coming away with a new collection of Astrantia and Phlox for the cottage garden borders. I am afraid my plant addiction was well and truly catered for!

April was a month for sowing seeds and pricking out and potting on early sown varieties. The polytunnel is full and I have gradually been moving plants out to harden off. We are in a pocket that holds frost so many have had a layer of fleece over them on cold nights. Tender plants such as Zinnia and Cosmos will need that extra bit of protection until we are out of frost danger. My last potential frost date is 10th May so as I write this, I am preparing for a planting frenzy on the 10th.

May has to be one of my favourite months in the gardening year. Not only are we so lucky in this area to be surrounded by so many wildflowers, but each day brings new growth in the garden borders as they start to fill up and flower. As much as I love the spring bulbs, my heart truly lies with the cottage garden perennial borders and the amazing show that they start to put on.

Things to do in May

Take Dahlia cuttings

I must start with Dahlia’s. Hopefully, you will have all potted up your Dahlia tubers and it will soon be

time to get them in the ground. Mine are currently hardening off in cold frames. I will take the opportunity to take some cuttings before they go in the ground - new plants for free! It really is quite simple to do:

  • When the shoots of the potted Dahlia tubers have reached about 10-12 cm in length they are ready to be cut away from the tuber. Take a clean, sharp knife and slice as close as possible to where the shoot emerges from the tuber.

  • Check to see if the shoot is hollow. Trim cleanly just below the next pair of leaves. Remove leaves from the lower half of the cutting stem and leave a pair of leaves at the top.

  • I place mine in a peat free compost mixed with some perlite to aid drainage and rooting. I put this in a cut off plastic bottle with drainage holes pierced in the bottom, rather than using seed trays or pots as you can then see if the roots are emerging.

  • Dip the base of the cutting into rooting powder and place in the container. Firm the cutting in and having top dressed with grit, water them well.

  • Place them in a propagator or cover with a clear polythene bag to conserve water and place in a warm position with light (not direct sunlight).

  • Check regularly and keep the cuttings moist and in about two-three weeks you will be able to see if the roots have developed. You can then place each one into its own pot to grow on over the summer.

The Chelsea Chop

The pruning of herbaceous perennials can be done during May and coincides with the Chelsea Flower Show. I usually take away sections of established plants by a third. This encourages them to bush and prolong the flowering period. Perennials that benefit from the chop include Phlox, Achillea, Campanula, Lysmachia and Solidago. I also cut back the wildflower areas to increase the flowering period.

Plant out annuals

I love the time when planting out arrives and I start to see all the pots empty and get put away until the succession seedlings are ready to be potted. I will be planting out a massive number of Zinnia, Clary Sage, Phlox, Cosmos, and Scabious to name a few. My Snapdragons have been very moody this season and the autumn sown ones are hardly ahead of the ones sown in January and February.

Sow biennials

Foxgloves, Sweet Rocket and Honesty can all be sown in May. These will germinate during the summer and can be pricked out and potted on in late summer when they will go dormant. They will provide early growing, strong plants for flowering in Spring/ early Summer next year.

I could add more things to do during May but that is enough to be going on with. I am looking forward to all the planting but especially the true start of the wedding season this month. I hope you enjoy the forecast heatwave for May, and I will be back to report progress in the cottage garden in June.

Happy gardening!



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