Do Wasps Return to the Same Nest Every Year? A Guide for Ashingdon Gardens

Greenhouses, cold frames and plant stores stay warm early in the year, so they deserve an early look when the first queens come out.

A warm start in the spring

Glass and polycarbonate trap heat, and a greenhouse can feel mild on a day when the rest of the garden is cold. For a queen emerging from hibernation in April, that warmth can be appealing, and the structure has plenty of dark corners behind staging, under benches and in the roof.

If wasps nested in or near a greenhouse last year, the colony has long since died. The old nest does not get used again. But the situation, a sheltered space with a few small gaps, is the sort a new queen may investigate.

For gardeners in Ashingdon who spend spring evenings among seedlings, a minute spent looking up and around the frame at the start of each session is a sensible habit.

Open the greenhouse door in the morning and let the warmth build gently, instead of throwing everything open at once. It gives any wasp inside a chance to leave quietly.

Where they tuck in

The usual places are the roof apex, the end of a ridge bar, gaps between panels and the junction where the frame meets the base. Plant pots stacked in a corner, rolled-up netting and folded fleece also give shelter, and a queen may be found on those long before any nest starts.

• Look at the underside of shelves and benches.
• Check behind propagator covers and spare trays.
• Examine any wooden base for splits.
• Look into the guttering and the door runners.

Go slowly, and open the door and vents before you start so a wasp has an easy way out.

In a polytunnel, the arch ribs and the ends where plastic is clamped to the frame can hide gaps. Cold frames with wooden surrounds may also hold a queen beneath the lid in early spring, so lift lids slowly and look before putting a hand in.

Check them again a fortnight later, because a queen that was absent on one visit may have settled by the next.

Write the dates in a notebook.

What if you disturb a queen

A single large wasp in spring, flying slowly and bumping into glass, is almost always a queen looking for a nest site. She is not an immediate threat, but she will sting if squashed or trapped. Open the door and vents and let her find her way out.

If she keeps returning to the same corner, she may be starting a nest. Watch from a distance for a few minutes. A small grey structure the size of a walnut hanging from a roof bar or frame is a starter nest, and now is the point at which treatment is simplest.

Do not knock it down. A queen who is disturbed will rebuild, perhaps somewhere less convenient.

If you are unsure whether it is a queen or just a drowsy wasp on a window, leave her alone for an hour and check again. Most will find the exit themselves.

Tidying in winter

When the greenhouse is empty in winter, clear out the old pots, wash down the staging and repair any broken panels or loose seals. Inspect the base for gaps where soil has washed away. Stored fleece and netting should be moved to sealed boxes.

If you find an old nest, check carefully that it is empty and remove it with gloves, placing it into a bag. If you are unsure, leave it alone and ask the technician at booking whether it can be taken down.

A clean, uncluttered greenhouse gives a queen fewer folds and corners to explore, and you will see her sooner if she does arrive.

Seeds, bulbs and tools stored in a box can be moved to a sealed container so nothing sits against the roof line. It is a small job that saves effort later in the year.

Make sure the greenhouse door fits well too, because a draught gap at the bottom is as inviting as a broken pane.

When the plants are growing

In summer, work in the greenhouse in the cooler parts of the day and keep the vents and door open for airflow. If you hear a buzzing that does not come from a flying insect, or see wasps running up and down the same strip of framing, back out and look from the outside.

Do not water or spray plants near a suspected nest. Disturbance of any kind makes the colony defensive.

Water butts, hose reels and stacked seed trays also give shelter. They are easy to forget, but a quick glance as you pass is enough, and it makes the difference between noticing a problem early and finding it late.

Gloves and sleeves are sensible when working in cluttered corners, even on mild days.

Sweep up and bin dead insects and dried leaves from the floor too.

Do this at a steady, unhurried pace.

Booking

Nests in greenhouses are straightforward for a technician, but they are unsafe for a householder to tackle. Call 01245 327274 or use the online form on our contact page. The charge is £90 per nest, fixed, with one visit guaranteed, and each additional nest on the property is £35 per nest.

We offer same-day service, are open seven days a week and cover homes and businesses. Please mention allergies when booking.

A note for commercial growers and garden centres: staff should know where to report a nest, and customers should be steered away from the area until it has been treated.

It is much easier to do this calmly if there is a plan in place before the season begins.

Frequently asked questions

More wasp advice for Ashingdon