Sustainable Environment
Sustainable Environment
We support alternatives to single use plastics
Consumption & Conservation
Consumption & Conservation
We harvest rainwater from our on-site reservoirs
Reduced Carbon Footprint
Reduced Carbon Footprint
With 80% of bedding plants grown onsite
Composting & Recycling
Composting & Recycling
We recycle over 90% of our on-site waste

What to do in the Garden: May

What to do in the Garden: May

Two Bank Holidays in May for many of us means that there is extra free time available to potter in the garden. It’s also a chance to enjoy some of the warmer days (fingers crossed) by sitting outside and admiring your well-tended borders!

If time is limited in the garden this month, here are our top ten tips:

1) Brighten borders with some of our lovely shrubs, climbers, herbaceous perennials and home-grown roses that are in stock now.

2) Start planting out your summer bedding plants (once the risk of frost has passed).

3) Clean up your walls, paving and patios ready for the BBQ season ahead!

4) Control slugs and snails to protect your bedding.

5) Plant out greenhouse tomatoes for a bumper crop!

6) Create a wildlife haven in your garden by planting flowers to attract pollinators such as lavender, heather and erysimum.

7) Lay new turf and reseed bare patches.

8) Repot greenhouse plants if necessary and control greenhouse pests.

9) Harden off plants raised from seed and cuttings.

10) Don’t forget your houseplants while you’re spending more time outside! Give them a spruce by top dressing the soil, remove the top few centimeters of soil and replace with fresh houseplant compost.

If you have a little more time to spare…

If your borders were looking a little crowded this spring, lift and divide bulbs that have finished flowering now, such as bluebells, fritillary, crocus and tulips, and lift daffodil clumps.

Harden off cutting of dahlias and chrysanthemums for planting out at the end of the month, along with tender bedding plants.

It’s time to get planting your summer bedding plants, but have some fleece on stand-by ready in case of any late frosts to protect summer bedding and other tender plants that you’ve planted out. Did you know we grow 80% of bedding plants on our nursery at The Gardener’s Garden Centre, Knockholt?

Hanging baskets can be planted up (if not done already) and hung out towards the end of the month, weather permitting.

Keep baskets and pots well-watered from now on as they will soon dry out, mix in Aquagel when planting to help retain moisture. We also recommend using plant food tablets to provide 6 months of slow release feeding.

May is the ideal month to prune trees and shrubs such as chaenomeles, choisya and early flowering clematis varieties, as a little careful pruning now will encourage improved shape and flowering next season. Speak to a member of the team on your next visit if you require any advice on pruning.

If you’re not looking for bedding, why not fill and brighten your borders with the wealth of shrubs and climbers we have to choose from, including: Ceanothus, choisya, rhododendrons, clematis (pruning group 1), wisteria and not to mention plenty of herbaceous perennials like aquilegia, dicentra, euphorbia, geraniums and peonies. If it’s roses you are after, we have plenty in stock! Remember, roses need plenty of feeding with a granular rose fertiliser such as AfterPlant Rose Food.



Sowing and planting edible crops:

If the night-time temperatures look set to dip, cover your peaches and apricots with horticultural fleece.

Continue successional sowings of radishes, carrots, beetroot, annual herbs and salad. Direct sow basil – the best way to grow it.

Earth up early crop potatoes when shoots are 9in high to prevent green potatoes.

Now’s the time to plant out greenhouse tomatoes for a bumper crop. Don’t forget to water regularly and support the plant. You can also plant out or direct sow half-hardy annuals, eg French beans, squash and pumpkins, when you are sure the frosts are over.


Once the frosts are over, plant out half-hardy annuals, and all of your dahlias and chrysanthemums. Start successional planting of gladioli and sow biennials, eg wallflowers, sweet williams and foxgloves.

Brassicas: kale, cauliflower, late purple sprouting broccoli, spring cabbage.
Roots: radishes, first carrots, first potatoes (raised inside).
Salad: salad leaves, first cos lettuce, pea tips.
Edible flowers: borage, marigolds.
Stems: rhubarb.
Leafy greens: chard, spinach.
Herbs: first dill, oregano, inside basil, first lovage, fennel, thyme, parsley, chervil, coriander, mint and tarragon.

In flower:
Tulips, alliums, autumn-sown hardy annuals such as marigolds, cornflowers, first sweet peas. You may also now be enjoying Euphorbias, Lysimachia atropurpurea ‘Beaujolais’, Viburnum opulus, early Peonies and Aquilegia.




May is a great time to have a clean-up in the garden and have it looking great for Summer. Walls, paving and patios that have taken a beating over the winter would benefit from a good scrub with a path and patio cleaner ready for all that summer dining.


Plant up new aquatic baskets with water lillies and oxygenating plants to aid your ponds ecosystem. Make sure your pond pumps and filters are running constantly.

Control slugs and snails to protect your bedding. We have a number of products in store to help control unwanted visitors in your garden. You can shop for these in our online shop.


Regular mowing usually becomes a priority this month. Add clippings to the compost heap sparingly, and mix with other organic matter. Prevent grass from creeping into the flower borders by edging the lawn with a half-moon edging iron.

Lay new turf and keep well-watered if a dry spell hits. In store, we sell turf by the roll with each roll sized 1m². To check stock levels, you may wish to call ahead beforehand.

Continue to reseed bare patches and feed established lawns.


Greenhouse plants will be growing at a good rate now so make sure you repot them into the next size pot if needed. Good greenhouse ventilation and regular watering is vital at this time of year to keep plants strong and healthy. The greenhouse is a great place to grow plants but it’s also a great place for pests to harbour too. So, watch out for pests and deal with any outbreaks as they occur.

French and Runner Beans should also be growing well now too. These can be sown direct into the soil at the end of the month (weather permitting).

Remember, to harden off plants raised from seed and cuttings by leaving them outside for gradually increasing periods of time. Start with the warmest part of the day, and build up to overnight. Doing this for a couple of weeks before they are planted out will help them establish in their new position.

Alastair specialises in roses, trees and acers so if you have any queries, have a chat next time you visit The Gardener’s Garden Centre, Knockholt!

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