The Fall Cleanup Checklist for Durham Homeowners

This is the one job that changes the outcome, and the received wisdom about it is about half right.

Michigan State has been running leaf mulching research on turf for over twenty years. Their extension guidance is to raise the deck to the highest setting on a dewy October morning and cross over the leaves once or twice, and they put the ceiling at up to six inches of leaves mulched at a time, depending on the mower.

Here is the corroboration that makes it worth acting on. Ontario's agriculture ministry publishes the same ceiling in metric: a layer of tree leaves up to 15 cm deep can be mulched into a lawn without adversely affecting it, using a mulching mower with sharp blades on dry leaves. Fifteen centimetres is six inches. An American land grant university and an Ontario ministry arrived at the same number independently, which is about as good as agreement gets in this trade.

The weed effect is real and the way it is usually quoted is not. Michigan State's own tip sheet says experience has shown that nearly a hundred per cent reduction in dandelions and crabgrass can be achieved after three years of mulching, and we want to be precise that this is their phrasing of accumulated experience rather than a trial result. What the trials themselves measured is more modest and more checkable: in a 1996 report from their turfgrass research centre, plots treated with mulched maple leaves carried 1.4 weeds per plot by September 20 against 12.4 in the untreated check. Application rates across their studies ran from 100 up to 450 pounds of dry leaves per thousand square feet.

Two results from those trials that are worth having because they kill common objections. Soil pH did not change across the duration of the field experiment. And organic matter went up rather than down: 7.5 per cent in the control, 8.4 under maple, 8.9 under oak.

Now the limit, stated by the same ministry that publishes the 15 cm figure. If fallen leaves are not removed, the lawn will not get light and will eventually die. Purdue says the same thing from the disease side and tells homeowners to rake and mow through the fall specifically to prevent the insulating effect of matted grass and accumulated leaves.

So the operating rule is not leave them or take them. It is this: leaves you can chop into pieces small enough to fall through the canopy are fertilizer. Leaves that sit whole and get wet are a tarpaulin. The line between the two is roughly six inches deep and it moves with how dry the leaves are and how good your mower is.

Plenty of operators sell a special short final cut for winter. We do not, and the reason is in the published guidance rather than in our scheduling preferences.

Purdue's fact sheet on grey snow mould says that continued mowing to a height of two and a half inches into the dormant period will decrease the risk. Their pink snow mould sheet goes further and says efforts should be made to maintain taller mown turf at two and a half to three inches to prevent the matting, because long lush growth and the insulating effect it creates extend the temperature window the disease can work in.

Two and a half to three inches is 6.4 to 7.6 cm. We cut at 7.5 cm all season. Which means the winter recommendation is already the height we were at in June, and there is nothing extra to sell you. Cornell puts the same instruction the simplest way: continue mowing turf as long as it continues growing in the fall.

What nobody in the acceptable research says is scalp it. Not one source we could find recommends dropping the deck for a final cut, and the two that discuss height going into winter both name a figure at or above three inches.

The practical version, on a Durham calendar: keep the weekly visit going into November for as long as the grass is still growing, at the same height, and stop when it stops. Growth on a cool season lawn here usually gives up somewhere in the second half of November, which is also when the truck switches over to the snow route.

Late season nitrogen is the third ranked job and it is the one with the best measured payoff.

Ontario publishes two applications and the rates for both: one from mid August to mid September at 0.5 kg of nitrogen per 100 square metres, and a late season one in mid to late October at the same rate, applied when the turf has stopped growing but is still green. The season total is 1.5 to 2 kg per 100 square metres across two to four applications, and in the absence of a soil test the province recommends a 4-1-2 ratio, something like a 20-5-10.

Purdue gives the imperial equivalent and puts the timing slightly later: 0.5 to 1.0 lb of nitrogen per 1,000 square feet, near or after the last mowing of the year while the lawn is still green, generally in the first few weeks of November. Their published list of what it buys is specific: better root development, stored energy reserves, colour retention, earlier green-up, improved density and better tolerance of spring diseases such as red thread.

Here is the conflict. Cornell says to apply fall fertilizer before October 1, specifically to avoid stimulating succulent growth ahead of freezing weather and feeding snow mould. Ontario and Purdue both endorse a mid to late October or November application.

We are not going to pretend those agree. What reconciles them is the condition attached to the later date by both Ontario and Purdue: after growth has stopped, while the plant is still green. The thing Cornell is warning against is lush new growth going into winter. A dormant application on a plant that has stopped growing does not produce lush growth; it produces root and stored reserve. The disagreement is really about whether you can be trusted to judge when growth has stopped, and the honest answer is that on a warm Ontario November plenty of people cannot.

One more thing on fall feeding, published by Ontario and easy to miss: rooting depth is proportional to mowing height, and a late season nitrogen application promotes deep rooting through the fall so the plant enters spring and summer with a better root system. The feeding and the cutting height are the same argument told twice.

This one is not about the lawn at all, and it is the job with the largest downside if it is skipped.

Natural Resources Canada publishes the explanation of ice damming, and the interesting part is that the worst case is the half insulated attic, not the uninsulated one. Their guidance is explicit: an uninsulated attic usually does not get ice dams, because the heat coming through melts the snow as it lands. A well sealed and insulated attic also does not, because the roof stays cold. The dam forms where the attic is warm enough to melt snow up high and the eave is cold enough to freeze the water when it gets there.

Their published remedy is not a heated cable. It is seal all attic air leaks and insulate thoroughly, with a ventilation ratio of 1 to 300, unobstructed vent area to insulated ceiling area, and about half of that as continuous soffit vents. They also note something you would never guess: a dark, south facing wall heated by the sun can drive warm convection up into the eave and cause damming from outside the house.

On the eavestrough itself, the federal flood guidance is specific and easy to act on. Discharge downspouts at least 2 m from the foundation, and from neighbouring foundations too. Install one downspout for every 6 to 12 m of eavestrough. And clean them at least twice a year, fall and spring, plus after a severe storm and when ice starts building up.

That two metre figure is the one most Durham subdivisions fail, because the lots are narrow and the splash block points straight at the neighbour's wall.

Two federal figures bracket the whole autumn on an Oshawa property, and they are worth writing on a calendar.

The average date of first fall frost is 14 to October 15, depending on which normals period you read, with a frost free season of about 167 to 168 days. Environment Canada also publishes the probability spread, which is more useful than the average: there is a ten per cent chance of the first freeze on or before October 5 and a ninety per cent chance it has happened by October 25.

Against that, the Region's last yard waste collection lands around December 10. So you have roughly eight weeks between the median first frost and the last chance to put leaves at the curb, and the useful part of that window is the first four, because December leaves are wet leaves and wet leaves are heavy.

The other date worth knowing for a different reason: Oshawa's December snowfall normal is 24.7 cm. November is 5.1. The idea that you have to finish before the snow arrives is true in December and mostly not true in November.

Andrew runs the business and works this list himself, in the order it is printed. North Oshawa, and the seven Durham towns the route covers, fully insured, an HST registrant. Six Durham winters of snow clearing sit behind that, his own rather than the company's, and the November changeover from mower to plow is done in a single afternoon.

The ranking at the top of this page is the order these nine jobs would be done in on his own property, which is why the presentation work sits ninth instead of first.

Sources here are ministries, municipalities, federal agencies and university extension programs, and every link is live so any line of it can be checked.