May is the month when the growth in our gardens really picks up. The perennials will have reemerged and now are starting to take up their places in the planting beds, with some (geums for example) already in flower, and others promising beautiful displays for the coming months. It’s a time full of potential and a joy to be outside observing the new growth and flowers unfurling. 

Next week looks set to be a scorcher so make sure you water your containers and any newly planted plants in your beds (this includes plants that have been in the ground for under a year or so). If possible, water early in the morning. This gives time for the plants to take up the water before the heat of the day causes it to evaporate from the soil’s surface, but also allows for foliage to dry out and not sit wet overnight which can sometimes lead to fungal diseases. Of course this isn’t always possible so an evening water is better than no water at all!

It’s important to be mindful of water use and use gathered rainwater if possible. Have you considered installing a water butt in your garden? You can fit them to downpipes on your house or a shed to collect the rainwater. It’s well worth the effort as it saves on water use and rainwater is better for plants and soil than tap water. 

As well as making sure no plants go thirsty this month, here are a few other things to be doing in the garden…

NO MOW MAY

First up is a job you can tick off straight away! Don’t mow your lawn. “No Mow May” is an initiative set up by Plantlife that encourages people to – you’ve guessed it! – not mow their lawn for the month of May. The benefits of this are huge for pollinators. Allowing wildflowers such as daisies, buttercups, clover and dandelions to bloom in your lawn provides nectar for them to eat. Plantlife run a wildflower survey at the end of May to record what flowers have shown up in the unmowed lawns too.  

If leaving your whole lawn unmown doesn’t work for you, why not leave a strip at the back or along the edges. Every little helps and we’ve written a blog about wilder lawns here that includes some ideas for wildflowers that you can add to your lawns that not only look beautiful but are great for pollinators too. Have a read here. 

Lastly, on the subject of lawns, if you have any patches that have gone bare or need relaying you should try to do this by the end of the month, or wait until the autumn. Sowing grass seed or laying new lawns in the summer is possible but requires much more maintenance and water so is best avoided if at all possible. 

BULB MAINTENANCE

By now most, if not all, of your Spring bulbs will be coming to an end. Make sure you deadhead them (tulips, narcissus, daffodils, fritillaria) to give the best chance of reblooming next year. Removing the flower stem will mean no energy is wasted making seeds and that it all goes back into the bulb. Once deadheaded, you must avoid the urge to cut back the remaining foliage but rather let it die back. When it’s yellowed it can be removed without much force at all (if any). Tulips can be a bit hit and miss as to whether they return, with some varieties being more perennial than others. It’s always worth checking how likely reflowering is when buying tulips if you want to try to ensure flowers for a few years. 

If you have any large clumps of bulbs that are getting a little crowded, you can lift and divide them now too. Carefully lift them from the ground (we find a garden fork most effective for this – don’t pull on the leaves), pull apart the cluster of bulbs into two sections, replant one in the existing space and plant the next where you want it to flower next year. Do water it in so as to help the bulbs settle in the new space. 

APHIDS

We have been seeing a lot of aphids around at the moment. If you are too, please don’t be tempted to reach for the chemicals. Instead, you can pick off the aphids and squash them if they are causing damage to your plants. Hopefully birds and ladybirds will be attracted to your gardens to help manage the aphid numbers, along with hoverfly and lacewings (the larvae of which each aphids too). We are seeing more sparrows in our gardens at the moment eating the aphids off our roses which is great. 

PRUNE SPRING FLOWERING SHRUBS

Spring flowering shrubs such as choysia, ribes, japanese quince, forsythia, spiraea and philadelphus can be pruned once they have finished flowering. First you can cut back the flowering stems. Take these back to a new shoot and be sure to take care with maintaining the overall shape of the shrub. Next, with large, established plants, you can remove a few of the oldest stems at ground level. This will reduce congestion and promote new growth. Check for any stems that are rubbing or growing into each other too. Lastly, as with all pruning, you should check for and remove any dead, damaged or diseased stems. 

Take care not to disturb any nesting birds. If you think there could be a nest in your shrub, it’s best to leave well alone. Pruning of hedgerows should ideally be avoided until after nesting season. 

TIE IN CLIMBERS

Climbing plants such as clematis, jasmines, honeysuckle and climbing roses should all be tied in as new growth emerges. This is to support the plant as it grows, direct the growth to cover the desired area and help prevent the stems getting damaged. Once the stems are long enough, use garden twine to tie them to the structure (whether that be flexible steel wires on a wall or pergola, an obelisk or over an archway for example). Regularly check on growth so as to support the plants as necessary. Spread out stems in a fan-like shape if you want to cover a flat wall, or try spiralling stems around pergola legs. 

PLANT OUT DAHLIAS AND SUMMER BULBS

Come mid to late May you can plant dahlias out into the ground. We always suggest choosing varieties with open flowers so that pollinators can benefit from them too. Dahlias provide wonderful colour from late summer until the first frosts and make for great cut flowers too. Some require staking so do check this when you plant them and get the stakes in place before they are needed. 

It’s also not too late to plant out summer flowering bulbs – plants such as gladioli, crocosmia, nerines and acidanthera murielae (also known as Abyssinian gladioli). These will still flower this year and add some extra colour (and nectar!) to your garden.

START HARDENING OFF SEEDLINGS

If you have grown any plants from seed, you can now start to harden them off. This just means get them used to the outside – both the cooler, more fluctuating temperatures and the wind. You can start this by opening cold frame doors and leaving them open during the day time, gradually moving to leaving them open at night before moving the seedlings out of them and into their new positions. If you don’t have a cold frame and are growing your seedlings indoors, you can put them on trays to take out during the day initially and again build up to leaving them out overnight before planting them in their position. 

SEED SOWING

It’s not too late to sow some seeds now if you fancy growing some border fillers or some veg. Some annuals such as cosmos and calendula can be sown directly where they are to flower now and will provide beautiful flowers that pollinators love too. Annuals are a great option for filling gaps in borders as well as providing colour and extra beauty to a garden. 

Carrots, beetroot and radishes can be sown now for a crop this year, and cut and come again lettuce too. Sowing lettuce every two to three weeks ensures a bounty of tender salad leaves throughout the summer and into autumn that you can keep picking as you want it.

We have previously written about successional sowing of veg to elongate the harvesting period so even if you have already sown some veggies, you may wish to sow some more now for a later harvest. Cauliflower and purple sprouting broccoli seeds can be sown now too for a winter harvest. 

DEADHEADING AND WEEDING

Repeat flowering roses may start to need deadheading soon. This is a job that will reward you with more blooms so it’s definitely worth doing. For aesthetic reasons, you will likely want to snip off individual spent blooms from flowering heads so that they don’t detract from the other flowers on that stem. You can do this simply by cutting the single flower off. Once the whole flowering head is finished you should remove the stem down to the first set of leaves. This will encourage new growth and more flowers. 

You can also deadhead geums at this time of year if they are going over. Be careful not to remove developing buds along the long flowering stems, just the spent flower head. 

Lastly, as ever, there may be weeding to do but we always caveat that with the reminder that weeds are just wild flowers. As long as they aren’t outcompeting your intended plants for space and nutrients, it’s fine to leave some for the pollinators to make use of. You can always remove them once they have flowered, before they go to seed, or leave them towards the backs of borders or in a designated “wild” area in your garden if space allows. 

We love May in the garden, there’s so much potential plus the first flowers to enjoy. We hope you manage to get some time out in yours this month. Happy gardening!