When is the best time of year to spray weeds?

While they are actively growing, which in Leicestershire runs from roughly late spring through to early autumn, and always on a dry day with no rain due for a few hours. A spray works by being drawn in through the leaves and carried down into the root, and that only happens when the plant is growing, so hitting a dormant winter weed mostly wastes the treatment.

The weeds that take hold in a drive, path or patio are tough perennials and grasses rooted down in the joints and sub-base, and the root is the part that has to die. A systemic weedkiller only reaches it when sap is moving, so the weed needs to be up, green and growing. That is why the window is the growing season, warm soil and active leaf growth, rather than a bare winter surface. Spring catches the weeds while they are young and taking up the treatment readily; early autumn is strong on established perennials, because as the plant pulls energy down to its roots for winter it carries the spray down with it. Spray outside that window and you are treating a plant that is barely drinking, so the root survives and the weeds are back.

The other half of the answer is the weather on the day. It needs to be dry, with no rain forecast for a few hours after, because rain landing too soon washes the spray off the leaves before the plant has taken it in, and that treatment is gone. Beating heat in a dry spell is no good either, as a stressed weed in a drought shuts down and takes up very little. A still, dry day in the growing season is the sweet spot. This is also why I keep the weather caveat honest: if rain is coming in too soon after a booking, I would rather move the job than spray it and watch it fail.

Timing is also why one spray a year is rarely enough to keep a hard surface clear. Weeds do not all come up at once. Fresh seed blows into the joints and germinates in flushes right through the season, and the glyphosate-type weedkiller I use kills what is growing but leaves nothing in the ground to stop the next lot, so a surface cleared in spring will often have new growth by mid-summer. That is exactly why I offer an optional plan of three visits a year, spring, mid-summer and early autumn, which maps straight onto how the growing season actually behaves. There is no contract and no direct debit, you pay per visit and can stop any time, and a surface I am already maintaining is a smaller job so it usually falls in the cheapest band.

Most of the timing advice you will find online is really about lawns, when to feed and when to use a selective weedkiller between the grass, which is not the same job as clearing a driveway, path, patio or gravel down to the root. I only do hard surfaces, across Leicestershire, and I am qualified to spray professional weedkiller, so the sensible move is to get it done properly at the right point in the season rather than guessing the day yourself. Prices start from £15, I quote a fixed price from a photo and your postcode within 24 hours, and if the weeds on the area I have treated have not visibly died within four weeks I come back and re-spray that area free.

Ready for a price? Send a photo of your weeds and I’ll text you a fixed price within 24 hours.