Homeowner guide
One week the porch is clear. The next, there are webs across the light, the corners of every window and the top of the garage door. Spider season on Lake Huron does not start on a date; it starts when the first warm week brings the overwintered spiders out and the first hatch off the lake gives them something to eat. Here is how the year goes for a home in Sarnia and Bright's Grove, Grand Bend, Bayfield, Goderich, Kincardine or Port Elgin, and what to do in each stretch of it.
The short answer: webs start appearing in May, build through June and July, look worst in August and September, and fade in October. The south end of the lake runs a week or two ahead of the north: Sarnia is usually moving by early May, while Kincardine and Port Elgin wait until the second half of the month. Within that pattern, the houses that suffer most are the ones with lights on all night and trees against the siding, whether they are one kilometre from the water or ten.
Cold weather makes outdoor spiders disappear from view, but not from the house. Some overwinter in sheltered spots behind shutters, under soffits and inside the gap at the top of the garage door. Occasional indoor sightings are normal. This is the time to walk the outside of the house on a mild day and note last year's trouble spots, check weatherstripping and door sweeps, and decide what you want to change about the porch and garage lighting before the season starts.
The first warm stretch, usually late April in Sarnia and mid May further north, wakes the overwintered spiders. New webs appear in the same sheltered corners as last year within days. Early in May the webs are small and the egg sacs from last fall are still tucked in the corners, which makes this the most valuable time of the whole year to take everything down. Remove the webs, the spiders and the sacs together, and you start the season from a much lower count than if you wait.
This is also when to put the porch and garage lights on a motion sensor or a timer, and to trim back any shrub or branch touching the wall. These two changes cut the insect traffic at the house before the hatch begins.
Lake Huron produces insects in pulses, and the mayfly (fishfly) emergence of mid June into July is the biggest, with midges in pulses from April to frost. After dark they fly inland in their millions and land on anything lit, which means the porch light, the coach lights on the garage and the glow from the front window. Within a week every one of those spots has a web beside it. Through July the pressure stays high, especially on the shaded side of the house and anywhere a tree stands close to the wall.
In these months the spiders are a maintenance problem rather than a danger. Keep taking the webs down on the porch and the first floor, keep an eye on the corners that refill fastest, and if the house is on a Season Plan, this is when the July visit lands.
By late summer the orb weavers that hatched in spring are full grown, and their webs are big enough to stretch across an entire window pane. The number of spiders may not be any higher than in July, but the webs are far more visible, and this is when most people decide something has to be done. The orb weavers also lay their egg sacs now, tucked under soffits and into frames, ready for next spring. Taking those down in September is what makes next May easier.
This is the stretch where a single visit does the most visible good, and why the Season Plan's third visit sits in September rather than earlier.
Cooling nights slow everything down. Some spiders die off, some settle into sheltered spots outside, and a few try to come indoors through gaps around doors and cables. A final pass on the entrances, a check of screens and door sweeps, and a look at the garage door seal are worth doing. Do not seal vents, weep holes or anything that needs to breathe. By December the outside of the house is quiet, and the cycle waits for the first warm week.
The order is the same whenever we come. Removal first: a backpack HEPA vacuum takes webs, spiders and egg sacs off everything within reach, including porch ceilings, lights, window and door frames, the garage door frame, first floor soffits and the foundation line. High eaves and peaks are swept down with a cobweb brush on a telescoping pole. Physical removal works instantly and does not wash off.
Then, only where activity justifies it, a targeted treatment goes on those sites. The product is registered in Canada, applied where the label allows at the lowest label rate that works, by a trained technician, supervised by our licensed exterminator, wearing what the label requires: long sleeves, long pants, chemical resistant gloves, and eye protection for overhead work, plus a respirator for overhead work as company policy. People and pets stay off treated areas until dry, with the time given in writing. A written summary after every visit says what was used and when each area is clear. We do not spray every wall of every house every month, because that puts more product around pets, gardens, pollinators and the lake than anyone needs.
The Season Plan is three visits, May, July and September, from $499, timed to the three turning points above. A single visit is from $199. Larger homes run about 30 percent more, and all prices are before HST for a standard home up to about 2,000 square feet, confirmed before work starts. If webs come back within 60 days on the areas we treated, we re-treat them the next day we are in your area at no charge; the guarantee page has the details. The full service is described on the spider control page, and because the south route starts in Sarnia, spring service begins there first; see the Sarnia and Bright's Grove page for timing at the south end of the lake.
Good to know
Along Lake Huron, May. The first warm week brings the overwintered spiders out, early May at the Sarnia end and mid to late May around Kincardine and Port Elgin. Some spiders are present in sheltered spots all winter; they just are not building webs you can see.
No. A cold wet spring pushes everything back a couple of weeks; a hot dry June brings the hatch and the webs on early. The pattern holds, the dates move. Watch the house, not the calendar, and start when the first fresh webs appear.
It means more insects at night, and the spiders follow. But a house ten kilometres inland with porch lights on all night and pines against the siding will often carry more webs than one closer to the water with a motion sensor and trimmed shrubs. Lighting and shelter matter more than distance.
Not sure what spider you have?See our guide to common spiders in Ontario, including the bridge orb weaver and the cross orb weaver.
