Gardening Jobs Checklist – May

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Welcome to the fifth instalment of twelve monthly blogs, these blogs will cover some of the many key gardening tasks that will need to be undertaken throughout the year.



Mow Lawns Weekly

Having a mowing regime is essential for maintaining a healthy lawn. Mowing frequency and cutting height will depend on the look you want to achieve, whether that be a ‘classic close-cut lawn or a longer wildlife-friendly one.

how to mow blog post

View my blog post ‘How to Mow’ to learn how to properly mow a lawn.

Essential lawn maintenance advice for May:

Regularly mow and add your clippings to a Compost heap.

Keep lawn edges trimmed: You can prevent your lawn from creeping into plant borders using a spade or half-moon edging iron to create a (3in) gutter around lawn edges. 

Use fertiliser: Encourage a healthy-looking lawn by using a high nitrogen summer lawn fertiliser; Always follow the manufacturer’s instructions carefully.


Sowing new lawns and over-seeding bare patches.

Preparation: Cultivate, Level and lightly firm the ground before sowing. 

Aftercare: Avoid walking over or mowing newly sown grass until it has reached a height of 2-3inches, and then only trim lightly at the highest setting. Prevent drying during dry days, and don’t worry about weed seedlings; these will disappear once regular mowing begins. 

Kill moss: Choose a combined fertiliser and moss killer if moss is a problem; Always take care to follow the manufacturer’s instructions. 


Earth Up Potatoes

What is earthing up? Earthing up or ridging / Hilling, as it’s often known as, is simply drawing up the soil into a ridge above a row of planted potatoes.

When should I earth up? When potato foliage starts to grow through the top of the drill, you should begin to earth up.

Why is earthing up important? Earthing up Potato plants as they grow protects early shoots from frost damage. Earthing up ensures developing potatoes aren’t exposed to light, which turns them green and poisonous.

How to earth up – Earthing up is best done with a garden hoe. Use the loose soil around the potato to form a peaked ridge to prevent your potatoes from becoming inedible; This may be required 2/3 times a season.


Frequently Asked Potato Questions

Can you re-use potato soil? If your potato crop had any sign of Blight this year, do not re-use the soil anywhere in your garden. A general rule when re-using any soil is to always think about crop rotation; Never use the same soil for the same vegetable year after year. 

How often should potatoes be watered? Potatoes need watering at 1 to 2 inches per week. Watering newly planted tubers too much or not enough as they begin to form can misshapen your potatoes.  

What can be planted after potatoes? When nutrients are replenished with a balanced organic fertiliser, a potato plot often makes a great place to grow cabbage family crops for autumn like Cabbage, Collards or Kale. Leeks or Scallions are good choices too.


Check hedges for nesting birds before trimming

It is important to check there are no birds nesting before undertaking work on a hedge.

It is an offence under the Wildlife & Countryside Act 1981 to damage or destroy the nest of any wild bird while it is in use or being built.

The bird nesting season is usually considered to run from March to August.


All hedges require initial pruning upon planting and maintenance trims to keep them within their bounds. Pruning times will vary depending on the type of hedge you own.

  • New deciduous hedges need pruning in Winter
  • New evergreen hedges need pruning in Spring
  • Established hedges can be pruned annually to keep them looking good


Greenhouse doors and vents

Greenhouses, whether of glass or plastic, are vulnerable to overheating from Spring until autumn. However, with sufficient Ventilation, shading and Humidity, many plants can tolerate those high greenhouse and conservatory temperatures. A gardeners main objective is to prevent leaf temperature from rising to levels that cause tissue damage. Shading should be reduced gradually by September and removed as soon as ventilation alone prevents overheating.


There are usually three places within a greenhouse that help control ventilation.

  1. The door 
  2. The roof vents 
  3. The side vents 

Small greenhouses have a higher glass to floor ratio, so they should ideally have more ridge ventilation. Unfortunately, these features are rarely provided, leaving amateur greenhouse gardeners vulnerable to overheating. Thankfully, the doors of most small greenhouses provide an alternative means of ventilation which partially compensates for the lack of roof vents. Side vents are helpful but less effective than roof ventilation.

Effective Ventilation Steps:

  1. Monitor the temperature of your greenhouse with a ‘Maximum-minimum thermometer’. Typically temperatures more than 27°C/81°F) can cause plant damage. 
  2. Watch for signs that shading and ventilation are needed, i.e. sun-flag (partial collapse) or leaf scorching.
  3. Open doors and vents on sunny days; Leave open at night if the temperatures remain high.
  4. It may be necessary to temporarily remove panes from glasshouses to assist with ventilation during heat waves.
  5. Consider also fitting automatic vent openers will ensure roof vents open when you are not around. 


Shading from mid Spring until early autumn is another way to decrease greenhouse temperatures. However, Shading also decreases the light plants receive. As plants depend on light to grow, only minimum Shading should be used. Sun-loving plants such as tomatoes, succulents don’t need Shading, although a shaded greenhouse is more pleasant environment to work in. 

Effective shading solutions

External blinds provide shade with maximum cooling effect and are easy to operate. However, they may interfere with vents and are one of the more expensive options available. 

Internal blinds. Unlike external blinds, internal blinds allow sunlight to pass through the glass and generate heat. However, there are a wide variety of materials available with varying permeability to allow for better airflow.

Polyethene mesh or shade netting: is a cheaper option than blinds; these tend to be attached with clips inside the greenhouse. External fitting is better but harder to manage. Polythene mesh is likely to suffer from UV damage over time but is cheap to replace. 

Shading paints: Some product examples include Varishade, Sunclear and Nixol; These are diluted with water and painted on the exterior side of glass panels during Spring. Thicker coats may be applied as the season’s progress. Wash and brush off the paint in early autumn.  Avoid using this product on unpainted timber greenhouses or structures glazed with polycarbonate or acrylic as visible traces may still remain after removal. 

Humidity: Dampening hard surfaces within the greenhouse, such as paths at-least three times a day, will help maintain a decent level of atmospheric humidity during bright sunny days. 


Thank you for taking the time to read my blog. I hope the above advice has helped you with your gardening for the month of May. Stay tuned for future monthly garden blogs by subscribing to my free email mailing list below

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