Gardening in May: Late Spring in Full Bloom

The month of May sees gardens all across the UK looking full of potential and vibrant. The soil is nice and warm, the risk of frost has passed and the air is filled with birdsong and the happy humming of bees. Gardening jobs in May are all about keeping that momentum going, nurturing growth, providing nutrients and relishing the results of all the work you did earlier in spring.

What to Do in the Garden in May

May gardening jobs are, for the most part, joyful and productive. It doesn’t take long for the results to show and the experienced gardener knows that this is just the precursor to a summer of beauty.

•    Mow lawns regularly, keeping the cutting blades sharp and raising the height of cut if dry weather is forecast.
•    Apply fertiliser to lawns
•    Apply wood preservative treatments to timber sheds and fences
•    Buy bedding plants and young vegetable plants from the garden centre
•    Plant main crop potatoes
•    Remove weeds as soon as they appear
•    Mulch around trees, shrubs and perennials
•    Turn home-made compost to accelerate the composting process

Flowers and Borders

Spring border care is intuitive and enjoyable. It’s all about nurturing plants and soil as they build momentum for eye-catching displays throughout the year.

•    Harden off tender plants and move them from the greenhouse to the garden
•    Continue deadheading spring flowering bulbs such as tulips and daffodils
•    Feed roses, perennials and newly planted borders with a general fertiliser. Many gardeners recommend using a high-phosphorus tomato feed to encourage flowers and fruits.
•    Watch out for slugs and snails around vegetable crops and tender plants. If necessary apply nematodes to control unwanted pests but please avoid using slug pellets.
•    Provide support for fast growing plants such as peonies, delphiniums and verbascum
•    If you are a fan of the ‘Chelsea Chop’ late May signals time to prune herbaceous perennials by up to half in order to encourage even more flowering shoots to form. 

Fruit and Vegetables

Nothing compares to the taste and texture of home grown fruit and veg and May signals the approach of harvest time for many winter planted or fast growing crops. Rhubarb will be ready to put into delicious crumbles, tangy micro greens and crunchy salad leaves can be on your plate within minutes of being gathered. And for the more adventurous of us, there is foraging to be done in the hedgerows.

• Continue sowing seeds for food crops either in pots or direct into the ground. Seeds to sow outdoors this month include pumpkins, courgettes, sweetcorn and beans.

• Sow salad crops, brassicas and root vegetables at 2-3 week intervals to ensure a successional harvest.

• Harvest rhubarb and freeze any excess to enjoy later in the year

• Plant out any young courgettes, brassicas and herbs that have been germinated in the greenhouse.

• Protect strawberry plants and other soft fruits from birds

• Earth up potatoes and keep the rows well 

Lawns and Hedges

For the most part, hedges should be left undisturbed in May in to allow nesting birds to rear their young in peace and safety. You may want to add a layer of mulch around hedge roots to help conserve moisture and nurture those all-important soil microbes.

It’s too late in the year to plant bare root plants but new hedges can be created using potted shrubs or instant hedging solutions. Be prepared to mulch well and water the new plants during dry weather.

Diligence with May lawn care will determine how well they lawn keeps it’s colour over the hotter summer months. A little bit of effort at this time of year will pay dividends later on.

• Mow lawns once or twice a week. 
• When mowing lawns in May, remember the one third rule. Never reduce the length of the lawn by more than one third in a single cut.
• Apply a spring-summer lawn feed according the manufacturers instruction.
• Remove lawn weeds by hand as soon as you spot them. If you do choose to use a herbicide, protect the environment by spot treating unwanted plants rather than blanket coat the entire lawn.
• Toys and furniture on the lawn must be moved regularly so that the grass plants have access to daylight.
• Mulch hedges
• Watch out for signs of blight on Buxus (box) hedging and take appropriate action if the disease is spotted.
   

Trees and Shrubs

With trees in full leaf and shrubs looking fantastic, May is a wonderful time of the year for gardeners and garden lovers alike. Here are a few May gardening jobs to keep your trees and shrubs in great shape.

•    Prune early flowering shrubs such as Forsythia, Ribes and Chaenomeles as soon as possible after the blooms have faded. 
•    Mulching trees in May will help them to thrive during a hot summer.
•    Recently planted trees will benefit from having hydration bags fitted - keep the bags topped up for the first 12-18 months after planting a tree.
•    For climbing shrubs such as Roses, Jasmine, Passion fruit or grape vines, tying in shoots will keep the plants tidy and protect them from wind damage.

Greenhouse, Indoor and Container Gardening

By May, most UK gardens can be confidently declared frost-free and so it’s safe move temperature sensitive plants from the greenhouse into the garden.

If you have started seedlings indoors or overwintered plants in the greenhouse, it’s crucial that you harden them off gradually. Move them out of the greenhouse for a few hours each day and little by little increase the time they spend out of doors until they are tough enough to spend the night under the stars.

Container gardening in May is all about ensuring plants have plenty of water and nutrients as well as providing sturdy supports for taller plants.

May greenhouse jobs also include:

• Keep doors and vents open on warm days - it may be worth investing in automatic openers.
• If necessary, shade or mist plants to prevent scorching or overheating.
• Watering, watering, watering! The smaller the container, the more often it will need irrigating.
• Water early in the morning or late in the evening in order to minimise evaporation.
• Feed plants weekly with liquid fertiliser
• Plant tomatoes, cucumbers and melons in the greenhouse or poly tunnel. Give each plant plenty of support and tie them in regularly - they’ll grow rapidly this month.

Wildlife and Sustainability Tips for May Gardening

• Provide shallow dishes of water for birds and insects. 
• Get involved with No Mow May[2.1] by leaving some areas of grass longer to create habitat for insects and small mammals. 
• Keep adding kitchen scraps to your compost heap. Suitable materials include anything that was once a plant. Potato peelings, those salad leaves that didn’t get eaten, biodegradable teabags or even shredded paper! Avoid adding cooked foods, meat and dairy though as they can attract vermin. Lawn clippings are great for compost provided the lawn hasn’t been treated with herbicides. Always balance lawn clippings with ‘brown’ waste such as straw or paper, so as to avoid anaerobic decomposition.
• Add pollinator friendly plants to your beds and borders
• Use recycled yoghurt pots, milk bottles and food trays imaginatively when pricking out seedlings (just remember to create drainage holes before adding plants)
• Collect rainwater in water butts and containers and use it to water your plants.

Seasonal Planting Ideas for May

It may seem a little premature, but planting now for autumn interest will pay dividends. Think dahlias, chrysanthemums, asters and achillea for late summer displays.

For the shorter term, your local garden centre staff will be able to give you lots of ideas for what to plant in May.

•    Sow seeds of sunflowers, nasturtiums, sweetcorn and squashes (including gourds)
•    Plant out summer flowers such as dahlias, pelargoniums and begonias and other bedding plants as soon as the risk of frost has passed.
•    Establish ‘soft’ herbs such as basil, coriander, parsley and mint in pots near the kitchen door
•    Create colourful displays in window boxes and containers - why not visit your local charity shop to source unusual containers.

May Garden Maintenance and Planning

May garden upkeep will certainly keep you out of mischief. At this time of year weeds are growing like - well - weeds, perennials and climbers are doing their best to fall over and timber structures in the garden are dry enough to receive a coat of preservative.

•    Weed and mulch borders regularly to keep them tidy and reduce competition for water and nutrients.
•    Provide supports for tall plants and climbers
•    In dry weather, water early morning or evening to reduce evaporation. Please check your local water authority website for any watering restrictions such as hosepipe bans.
•    Plant summer bedding and order autumn-flowering bulbs
•    Treat outdoor timber with suitable preservatives
•    Sweep paths, patios and steps 
•    Check and clean pond filters
•    Start planning planting schemes for autumn and winter. Hiring a garden designer or a horticulturist to create a personalised planting plan for your garden is an excellent investment.

Quick Checklist for May Garden Tasks

Here is your May gardening checklist of essential jobs to do

•    In the vegetable patch, plant out courgettes, beans and sweetcorn
•    Harden off and move tender plants outdoors
•    Feed lawns and mow them regularly
•    Deadhead the last of the spring flowering bulbs
•    Mulch trees, shrubs and flower borders
•    Water regularly during dry spells - provided there are no restrictions in place
•    Treat timber structures and furniture with appropriate preservatives

Finally - and arguably the most important thing to do in the garden in May - relax, enjoy the weather and admire the fruits of your labour. 

FAQs: Gardening in May