Ask This Old House Season 24 Episode 6: Sustainable Grass, Nail Shanks, and Driveway Lights That Don't Annoy Neighbors

Season 24, Episode 6 of Ask This Old House sends Jenn Nawada back to a Rhode Island sod farm, hands Tom Silva a tray of nails, and drops Heath Eastman in front of a house where guests feel their way up a pitch-black driveway. The two field segments look unrelated on paper. They aren't. Both are about reducing how often a homeowner has to intervene: the meadow you mow once a year, the exterior lights that turn on without a trip to the basement.

Tom's nail lesson is the quiet third leg of that stool. Match the fastener to the material and the assembly stops working itself loose, which is the same goal as the other two jobs, only twelve inches off the ground.

Jenn Nawada Returns to the Rhode Island Sod Farm

Jenn has been to this farm before — in 2018, with Roger Cook and Kevin O'Connor, to look at a microclover blend that needed no fertilizer, no pesticide, and minimal water. Pat, the grower, has since moved on to other sustainables, and what he shows her this time is a tray of wildflowers grown in the greenhouse: roughly twenty varieties spanning annuals, perennials, and biennials, deliberately stacked so something is blooming in every season rather than one big flush in June.

At six to eight weeks the roots are already tight enough that Jenn calls them rugged, and that matters, because the whole product depends on the mat holding together. Pat has her plant the way she'd plant sod. Prepare four to six inches of loam. Lay the mats close. Stagger the joints instead of lining them up, which is the same instinct that keeps brick and shingle courses from cracking along a continuous seam.

The more interesting material is out in the experimental field. Pat has been cutting test strips from a meadow mix built on sheep's fescue, and the fescue is the structural member of that assembly. Wildflowers alone won't knit into a rollable mat, so the fine-bladed grass holds everything together long enough to harvest it. In a couple of weeks that same field will be deep purples and pinks. Right now it looks like a field.

Maintenance is the pitch. Once you get a killing frost in the fall, mow it down. The seeds drop where they fall, and the stand reseeds itself. Pat's two-year-old test field has been mowed several times and keeps coming back. That's a genuinely low-input planting, and it's the kind of long view that landscaping segments rarely get to take. Jenn points out where it fits: the 200-foot buffer zone many homeowners have to respect next to conservation land, hillsides prone to erosion, droughty spots where conventional turf gives up. Pat adds that the pure sheep's fescue has mostly gone to golf courses so far, partly because it's finer-bladed than the wider-bladed turf a homeowner normally orders.

If Jenn's earlier Idaho project is your reference point for how she handles planting beds and path edges, this is the same designer instinct applied to a seed mix instead of a patio (Idaho Backyard Makeover, Window Wells, Welding). Less hardscape, more living material doing the work.

Tom Silva Breaks Down Nails by Head, Shank, and Job

Every nail has three parts: a head, a shank, and a wedge-shaped point. Tom's whole segment is about how those three parts change for the material you're fastening, and Kevin plays the straight man well here because the questions are the ones a homeowner actually has.

Heads first. The waffle, or corrugated, head exists because plastic-coated framing nails are slick, and a waffle gives the hammer face something to bite so it doesn't glance off on contact. A trim or finish nail has a head small enough to disappear — you overdrive it below the surface with a nail set sized to the shallow depression on top of the head, then fill the hole. Tom is clear that he doesn't like trim nails outside, because exterior wood moves enough to work a small head loose. Out there he reaches for a common or flat-head nail, sets it, and fills it.

Duplex nails get their second head for a different reason entirely: they're for temporary work. Concrete formwork and framing come apart later, and the upper head gives you something to grab with a hammer or a bar so you can save the lumber. If you've ever pried apart something that was assembled with the wrong fastener, you understand why he bothered to explain it.

Shanks do the holding. Smooth shanks are fine for most work. Ring, or cup, shanks grab fibers mechanically — Tom uses underlayment over an existing subfloor as the example, where the nail isn't reaching structure and its only hope is that the wood fibers snap into the cups. Spiral shanks twist as they drive and hold hard in framing. Kevin notes that a subfloor fastened with spirals is a bear to remove, and Tom agrees: you'll be reaching for a cat's paw, and you'll probably snap a few heads off first.

Heath Eastman Lights a Dark Driveway Without Blinding the Neighbors

Jen's house has four lighting problems wearing a trench coat. A fixture at the top of the spiral staircase throws almost nothing. A light at the basement stairs actually works, but the switch is inside the basement, so nobody uses it. A garage floodlight requires walking into the garage to turn on and, once on, throws hard enough that Jen has already decided she doesn't want to be those neighbors.

Heath lays out three approaches. Standard 24-volt LED tape, flexible, cuttable, running off a plug-in power supply at an exterior receptacle. A 120-volt continuous strip that plugs directly into the receptacle with no driver, which is the friendliest of the three to install. Or 12-volt landscape wall fixtures on a transformer, which is what Jen picks, drawn to the way the light washes downward instead of out into someone's window.

There's a design decision buried in that choice. Heath points out that a path light mostly guides the eye and doesn't throw much distance, whereas the wall fixture will actually illuminate the driveway surface. Then the expandability question: because the transformer he installs is larger than the current load requires, Jen can add fixtures later without replacing the heart of the system.

Layout starts at the center of the run and steps out about six feet in each direction, adjusted around a spigot, dryer vents, and a water heater vent along the water table. He mounts the fixtures low on that board, then cuts a small groove at each mark so the wire tucks up behind the trim instead of drooping below it — a small detail that determines whether the finished job reads as a lighting design or as a wire run.

The underground portions of this kind of work are what television compresses hardest. Pulling and stapling the cable beneath the board, leaving service loops at each fixture location, splicing conductors with set-screw connectors, sliding on heat-shrink sleeves and heating them until sealant weeps out the end: none of that is glamorous, and all of it is what keeps a low-voltage system alive through a New England winter. Heath also keeps polarity straight by tracking which conductor is ribbed and which is smooth, and matches that order at the transformer terminals.

Fixture Swaps, Ground-First Wiring, and a Smart Switch That Needed a Neutral

The garage fixture comparison is worth a minute. A bullet-style LED flood throws a hard, concentrated beam that can carry into a neighbor's window. A wall pack is flatter and more commercial-looking, but it pushes light out over the driveway at a softer angle. Jen picks the wall pack, and the reasoning is the same one Heath used on the wall fixtures: control the direction, not just the output.

Then the swap itself, which Jen performs. Power off, center cover off, retaining screw out, black and white and ground disconnected, fixture bar removed. The new bar goes on the same way, and Heath shows her to snug the screws while leaving the housing enough play to self-center. Ground screw gets loosened rather than removed so the ground wire can wrap it. When the new fixture goes up, the order is ground, white, black — Tom's rule, restated: ground is always the first connection made and the last one broken. On the side-of-house fixtures Heath installs a proper 10-32 ground screw into the threaded hole in the box rather than trusting a sheet-metal screw to carry fault current. That's the kind of thing nobody notices until it matters.

The smart switches are where I'd want an electrician in the room. The basement box holds a feed, a load out to the fixture, and a ground, but the smart switch needs a neutral it doesn't have. Heath pulls another switch out of the box to find the bundled neutrals coiled at the back, adds a pigtail, and tucks everything back. Five wires land on the new switch: ground to bare copper, white to the neutral, blue capped off because there's no second switch location on this circuit, black to constant power, red to the light. Then the low-voltage side joins the smart system through an outdoor smart plug that powers the transformer.

If you followed Heath's three-way smart switch work earlier this season, this is the same puzzle with fewer wires (Garage Overhead Storage, 3-Way Smart Switches, and the $40 Anode Rod). In that episode the traveler wire was the complication. Here it's the neutral, which is the one wire a lot of older switch boxes simply don't have available where you need it.

DIY Confidence Scale

• Wildflower mats and sheep's fescue — 3/10. Laying mats edge to edge and staggering joints is genuinely easy. Getting four to six inches of proper loam under them is the part that will eat your weekend, and skipping it is why most of these plantings fail.
• Nail selection — 1/10 as a skill, high stakes as a habit. Not a project, but the head-and-shank logic is free knowledge that prevents callbacks on decks, subfloors, and trim.
• Landscape wall fixture installation — 6/10. Mounting, grooving, and splicing are manageable. Terminating a 12-volt run, keeping polarity straight, and sealing every connection so it survives freeze-thaw is where sloppy work shows up two winters later.
• Exterior fixture swap — 5/10. Kill the breaker, verify with a tester, and follow ground-first, ground-last. Beyond that it's screws and wire nuts.
• Smart switch with a neutral pigtail — 8/10. Adding a conductor to a bundled neutral inside a crowded box is not a beginner's first electrical project, and it isn't the place to learn what a neutral is.

Additional Resources

• Watch on PBS
• Official This Old House episode page

The meadow mix and the driveway lights are the same purchase in different packaging: you pay more attention up front so you can stop paying attention later. Which of those two would you actually maintain once a year instead of forgetting entirely?