Greenhouse Maintenance Tips for Novice Gardeners

Greenhouse maintenance tips for novice gardeners is a starting point for newbie greenhouse gardeners to learn what needs doing. Its also a checklist for those who just need a reminder of the necessary greenhouse tasks!

Having said that, it should be pointed out that as greenhouses vary in size and the materials they’re made of, some of the points are of necessity general. There are blog links at the end for more on how to carry out these and other tips.

What is your Greenhouse used for?

For example, do you use your greenhouse for –

sowing seeds and growing cuttings
over wintering alpines and tender perennials
growing vines, melons, cucumbers
a permanent or semi-permanent display of tender and exotic plants

How often the greenhouse is used may mean some maintenance tasks are forgotten, or that it is difficult to empty the greenhouse to carry them out. We are all of us guilty of these excuses. But working out what needs to be done and when, creating a checklist, if you like, will make maintaining your greenhouse so much easier.

And importantly, who uses the greenhouse? Do you just need to think of yourself, the main gardener? Or are there other family members to consider? How able bodied are these people (including you!)

Around the Greenhouse

Although greenhouse maintenance obviously refers to the building itself (and we’re coming to that) the area immediately adjacent should form part of your checklist as it will impact on the structure and your use of it. For example, what grows near, and how easy it is to get to the greenhouse.

Paths

Paths and walkways should have safe and easy access for the people using the greenhouse, equipment and plants. For example, an uneven brick path may be considered quaint, but is it practical?
Ask yourself –

Are the paths wide enough for wheelbarrows and / or wheelchairs?
How even or level is the surface and is it slippery?
Is there access all round the greenhouse for maintenance?

Plants

Trees and shrubs may be providing shelter from the wind and shade in summer, but –

Are they evergreen or deciduous?
Deciduous will drop leaves in autumn to be cleared away from gutters.
Evergreens will lose fewer leaves but do so year round.
They will need to be pruned to ensure that branches are not overhanging or scratching the windows.

Greenhouse with cacti and tender plants, Downe House, Darwins home, Knet, wooden water barrel, blue wooden door, brick half wall to greenhouse

Adjacent sundries and structures

Cold frames and water butts are the two most likely and may be physically attached to the greenhouse.
Cold frames – follow general care for greenhouse frame

Water butts –

check for leaks, including around the tap
does the downpipe still fit cleanly in the gutter
is there a means of controlling overflow? This may be a valve in the downpipe re-directing the flow to a soak away when the butt is full

Greenhouse Maintenance – the Exterior

You may find binoculars and a ladder useful for closer inspection. If using a ladder, be careful, falling through glass panes onto steel-edged staging is not recommended as part of your greenhouse maintenance tasks! If you’re lucky enough to have a seriously large glasshouse, it may be appropriate to bring in a specialised team who have the equipment to clamber over large expanses of glass.

General

check all panes of glass for cracks and ensure they’re firmly fixed in place within frame
check ridge for any signs of movement
lean-to glasshouses – check flashing where it joins the wall
windows, louvres and doors should fit within frames without gaps
use a level to check for general movement of the frame
is there moss growing? – on a wooden greenhouse this may highlight a specific problem with rotting wood as well as generic dampness

guttering and downpipes –

some models have integral guttering
check fittings are secure and that the guttering hasn’t slipped
are there any cracks to cause leaks?
do the sections all fit cleanly together
does the water drain into a butt or soak away? If the latter, is it clear? For example, no leaves clogging a drain cover.

octagonal greenhouse, arch, trellis, vegetable area with raised beds and wooden greenhouse, grow your own

Wooden Greenhouse Maintenance

Check the frame for rotting, splitting, warping and splinters. Do the joints matchup? If not, is this because of general movement or due to a particular part of the frame.

If it’s a softwood rather than hardwood structure then regular cleaning and application of preservative will be necessary. Greenhouses are more likely to be hardwood than softwood as its far more durable. I would still recommend doing the checks and cleaning although preservative is not generally required.

If there are upvc or metal clips on vulnerable areas, check these are secure and in good repair.

Does the structure sit on a low brick wall, metal plate or onto concrete? Check all round for movement of the frame off this base. The brick wall should be checked –
could it do with a clean?
does it need re-pointing?
is it still straight?
There may be vents set into the brick – are they clear so air can pass through? If there’s a closing mechanism does this still function smoothly?

Metal Greenhouse Maintenance

Most metal-framed greenhouses are made of aluminium which has the potential to ‘corrode’, rather than ‘rust’. This corrosion looks like a white bloom that grows on the metal. Generally it is slower to appear and is not as detrimental as rust.

Aluminium also twists and bends under stress such as gales. So look over the structure for signs of this. There may be reinforcing plates in corners and across sections to reduce this happening. Check these for movement.

Greenhouse Maintenance – the Interior

Check the frame on the inside, including: –

the fit of windows, louvres and doors
how secure the window panes are in their frames – ie clips, putty, etc
opening mechanisms –
- manual – are all fittings in good repair, do they open and close easily?
- automatic / powered – basic checks can be carried out, for example can you see any loose screws? Are the vents and windows opening and closing when they should be?
- If a full inspection is needed, its worth asking your greenhouse installer, manufacturer or mower / garden power tool repair firm if they can help.

Flooring

The maintenance required will depend non the material. Domestic greenhouses are most likely to be concrete or pavers, but older ones may be brick or tiles. However the basics for all include –

is it level?
are there cracks?
is standing water an issue? Check levels
can water spillage easily drain away without causing a potential slip hazard?
is a broom easily reached to sweep away soil spillage

Greenhouse care tip – case study

If, for example, your greenhouse has water coming in on one side that pools then slowly seeps away from the opposite side, then there is a slight slope. You may be able to prevent water ingress by sealing around the higher edge of the greenhouse where it sits on the base.
This problem is most common with aluminum greenhouses on a solid base covering the whole floor area. One of your greenhouse maintenance tasks would be to check the seal is in good repair and replace it if not.

metal greenhouse in garden, herbs, garden spade

Heating

Most domestic greenhouses have a heater rather than a heating system. The heater if electric should be checked by an electrician (see below) Paraffin and other free standing heaters should be sent for regular service and maintenance. Should you have a more complex heating system, you’re likely to have a maintenance contract.

Basic checks you can carry out would include temperature settings. Is it warming up as it should / is the thermostat working properly?

Electrics

Whilst checking if there are any obvious loose wires or switches is basic maintenance, electrical testing of supply and equipment should be carried out by a qualified electrician. This may be annual or tri-annual so the timing should be noted down and inspection booked.

Remember water and electricity do not mix. So leaving full watering cans next to live sockets is probably not advisable…

Staging, Shelves

As well as checking the tops for wear and tear, check underneath. For example, are the supporting struts bent or missing screws?
All staging should be checked and cleaned, preferably twice a year, but certainly annually to prevent problems. You don’t really want the staging to collapse under the weight of all your precious plants do you?

Rust or bloom on metal should be treated.
If you have wooden staging, and damp is a problem check for rotting.
Wooden staging may need a coat of plant friendly preservative.

Windows – insulation and shading

An unheated greenhouse may have insulation added on the inside. This may be attached by clips which may remain to support shading for the summer. Check the clips are all there and still firmly in place. Insulation and shading is re-usable so roll it up and store out of season.

wooden greenhouse, raised beds Photo by Anna Guerrero from Pexels;

And finally

Saying “When everything has been checked, it needs to be cleaned, repaired or replaced as appropriate.“ Would probably send you running away – but don’t panic as I’m not going to say that at all!

Not all of the tasks have to be carried out at the same time or with the same frequency. There are blog links below which cover the ‘how to’ aspect of these tasks in more detail as well as suggesting when is a good time to carry them out.

And if you’re just at the stage of wondering about getting a greenhouse there are also blogs on helping plan and choose the right one and where the best place is for it to go in your garden.

So relax with a cup of coffee, get out pen and notebook or excel spreadsheet and start by making a list that is relevant for you and your greenhouse using the above tips and those below to help you.

If you would like to learn how to garden in your greenhouse, or help with finding the right greenhouse or alpine house to suit your treasured collection of plants, do get in touch. Plews is able to offer Gardening Lessons, Garden Design and Planting Designs or a Garden Consultancy Visit to suit your needs. Please check out relevant pages on the website for more details

For further gardening tips and inspiration check out Plews Potting Shed blogs, including the selection below – and find us on Instagram and Facebook