Gardening Tips

May mayhem! Grow-how tips for late spring


A great many aspects of our normal lives have stalled during these strange and difficult Covid times, but the garden certainly hasn’t! Lots of glorious spring sunshine and now some much-needed rain have brought the plants on with wild abandon and there is much to be done. Let’s get going with trimming some some perennials, making softwood cuttings and thinning veg seedlings amongst other things…………..

I want flowers ALL summer!

If you’ve got lots of perennial plants in your flower garden – and regular readers of this column will know that I LOVE perennials! – then they will be putting on masses of growth right now, ready to flower in June, July or August. I’m referring to things like perennial daisies of all kinds (Anthemis, Argyranthemum, Helianthus etc.), goldenrod (Solidago), campanulas (like the lovely feature pic), eupatoriums, catmints, aconites, lamiums, delphiniums, sedums and so on. Now obviously you can just leave them be, to flower themselves bonkers at their usual time and then maybe cut them back when they begin to look a bit tatty in the hope of a few more flowers after a lull of 6 weeks or so.

But there is a rather neat trick that you can do now, to prevent that lull. It is a bit time-consuming, but I’m thinking that that is something that quite a lot of us have a little more of, at the moment………………..

Anthemis "Sauce Hollandaise'
Anthemis ‘Sauce Hollandaise’ – see if you can make it flower the whole summer……

Go through the clump of shoots with your secateurs, choosing various stems at random to cut back by about half their length. This will delaying the flowering on those shoots, whereas the ones you didn’t touch will flower at their usual time – BINGO, you’ll have blooms on the plant for months rather than weeks!

Nepeta - catmint
Taking back some catmint shoots so that it will have flowers for AGES!

As I say, it is rather labour-intensive, and certainly more of a fag than grabbing the whole clump and reducing it by half – that is the well-known ‘Chelsea-chopping’ which makes the entire plant flower a month later than it was expecting to. But if you are after a really long flowering period, then do have a go with this technique. Why not try it on just one or two plants this year, and see if you like the effect?

Softwood cuttings for all

I simply had to put this next topic just below the one about chopping some shoots off perennials, because you can use some of those choppings to make new plants – how cool is that?! Bits of new growth taken off perennials, as well as a load of other plants like fuchsias, Lavatera, buddleias, hydrangeas, pelargoniums, Physocarpus, Euonymus, Sambucus (elder), penstemons, all sorts of perennial herbs, bedding plants……. can be used as softwood cuttings. Since you already have the plant, this is a free, and easy, way of making new plants to increase your stock or give away to friends.

Lavatera olbia rosea
Lavatera olbia ‘Rosea’- perfect for some cuttings taken now

You just need to go out early in the morning and collect some shoots about 4″ (10 cm) long – they should be full of sap at that time. Try to cut just below a pair of leaves if possible. Pop them into a plastic bag straight away – it is very important that they don’t dry out at all.

Stick your cuttings in a glass of water in the fridge if you can’t deal with them immediately. As soon as you can, fill some pots with compost to which you’ve added some grit or vermiculite if you have it – but don’t worry if you haven’t; this kind of cutting is actually quite forgiving, and remember you’ve lost nothing even if none of your cuttings work!

Taking shoots for softwood cuttings

Take off the lower leaves of each cutting, and pinch out the soft tip. If you happen to have some hormone rooting powder or liquid, this would be to time to dip your cutting in that. Make holes (3-6, depending on the size of the pot) round the edge of your pot of compost with a pencil, and put your cuttings in the holes with the lowest pair of remaining leaves just above the surface. Water and label the pot then put it into a closed propagator box, or just fix a clear plastic bag over it with a rubber band. This is to keep the humidity round the shoots as high as you can, but take off the bag twice a week for a few minutes – you don’t want the humidity to be so high that the stems start to rot! Leave it in a warm place but not roasting sunlight for your cuttings to root, and keep the compost moist.

Hydrangea cuttings all tucked up in a plastic bag

You’ll know your adventure has worked if you start to see some signs of new growth on the shoots in 2-4 weeks. Slowly increase the time your cuttings spend out of the propagator/plastic bag to ‘harden’ them up, before moving each plant to its individual pot for growing on and eventually planting out.

Sage cutting
Here’s one I did earlier! A sage shoot that I cut off 4 weeks ago, and is now growing on happily in its own pot.

Honestly, I urge you to try it, even if you have never done anything like this before. It is a total thrill when a random piece of stem suddenly morphs into a whole new plant!

Prune the spring-flowerers

Now that the spring shrubs have done their beautiful best to cheer us up, it’s time to repay them with a bit of clever pruning. Plants like Forsythia, Coronilla, Chaemomeles or Kerria will flower next spring on the stems that they make this year, and what you need to do is encourage them to make some strong young growth like that, which will flower much better than the old branches.

Coronilla glauca
Coronilla glauca – a spring-flowering shrub to prune now

Tidy up the stems that have flowered, but also chop down a few of the oldest ones right down at the base of the plant. It will have the effect of allowing air and light right into the middle of the shrub, and will spur it into growing some fabulous new shoots from right at the bottom. A nice drink of water and a sprinkle of fertiliser, and you can leave your spring shrub to get on with it until it bursts into glorious flower again in spring 2021.

Gardening Shorts

If you had some of those pretty cyclamen flowering indoors over Christmas or early spring, now’s the time to stop watering them. The corm needs to be allowed to go dormant, so take the pot outside and leave it tipped over on its side in a shady out-of-the-way place for the summer. In August, you can start watering again, bringing it into growth once more.

Stop watering pots of cyclamen now and give them some downtime.

If you have been hardening off your sweetpea seedlings by leaving them out during the day and bringing them in at night, you can now plant them out into your pots or the border. Put in the supports first for them to scramble up. If you live in a chilly part of the country, cover them up with a bit of horticultural fleece at night if a late frost is expected.

Sweetpeas - planting out
Planting out sweetpeas with supports to help them climb

Do thin out rows of veg seedlings before they start to impinge on each other, or you’ll end up with a lot of very weak thin plants that won’t do what you are hoping for!

One last plea – with so little traffic or extraneous ‘human’ noise during this strange spring, take time to listen to the birds. The singing of songbirds usually reaches its zenith in early May in this country, and we may never again have such an opportunity to stop and hear so clearly that marvellous and moving chorus.

NB: If you missed it, here is the link to Wednesdays DYOFC blog in which we were talking about runner beans, risotto and barn owls

Laura’s glasshouse

NB: At 10.30am on Sunday Laura (middle growbag) will be ‘live’ on Facebook taking you on a short tour of her glasshouse and gravel bed. If you’re on Facebook we’d love you to join the3growbags page so you can see her and if you’re not on Facebook – fancy giving it a go? You can always delete your account afterwards! – just click on the Facebook icon at the side of this blog. Laura’s never done this before so really be braced for the unexpected….

More NB: If you’d like to get a bit more gardening chit-chat from the3growbags, we’d love you to subscribe to our weekly posts

By the3growbags

We're three sisters who love gardening, plants and even the science of horticulture but we're not all experts. We'd love everyone even remotely interested in their gardens to be part of our blogsite.

6 replies on “May mayhem! Grow-how tips for late spring”

Hi! My coronilla was a baby from my mum’s garden last summer. It’s grown well but no flowers. Should I still cut it back? Thanks in advance and for your cheerful selves. Nearly as important as Gardeners World ?

Hi Susan, Elaine here. Thank you for your lovely comment! No, if your coronilla is still a baby, I would say that there is no reason to do anything to it for 2-3 years, because all its stems will be young and vigorous. As long as it’s growing in a sunny spot, it should be fine. Enjoy the pretty foliage this year, and cross your fingers for gorgeous blooms next year…….

Hello, Thanks for your lovely helpful and witty blog. I, too, have watched in awe as a tiny piece of sage has just morphed into a whole new plant. I’m now trying to propagate some roses. Hmm, we’ll see.

Thank you, Anna. Elaine here. I honestly think growing things from cuttings is almost as magical as sowing seeds. Good luck with the rose-cuttings – just remember that if they do grow, they will be on their own roots, which might mean either that they don’t have as much of the vigour of the parent plant, or that they have too much, as Laura was pointing out recently in our blog when a cutting I gave her of R.’Charles de Mills’ took over a big chunk of her garden!

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