Spring landscaping in Pittsburgh — month by month.

Spring Landscaping in Pittsburgh: Why Timing Is Everything

Spring in Pittsburgh doesn’t arrive all at once. It shows up in pieces — a warm day in late February that melts the last snowpack, followed by three more weeks of gray and freezing rain. The daffodils push up in March, and then a late frost knocks them sideways. By mid-April things start to feel real, but you’ll still see 30-degree mornings into May.

That staggered arrival matters for landscaping. Jump the gun on cleanup or planting and you’ll damage plants that aren’t ready, compact soil that’s still saturated, or waste mulch that gets washed out by spring rains. Wait too long and weeds get a head start, the lawn thins out, and your neighbor’s yard is already looking sharp while yours still has leaf piles from November.

This guide breaks spring landscaping in the Pittsburgh area down by month — what to do, when to do it, and why the timing matters. Whether you handle it yourself or call T&T Landscaping to take care of it, the sequence is the same.

March — Cleanup and Assessment

When should I start spring yard cleanup?

March is cleanup month. The snow is mostly gone, the ground is thawing, and the mess that winter left behind is fully visible. This is not the time to plant, mulch, or mow — the soil is too wet and cold for any of that. But it’s the right time to clear the way for everything that’s coming.

Rake matted leaves off the lawn. Leaves that sat under snow all winter form a dense mat that smothers grass, traps moisture, and breeds fungal disease. Rake them off the lawn and out of planting beds. If they’re too matted to rake easily, a leaf blower on low can break them loose. Don’t leave them — a smothered lawn in March means bare spots in May.

Clear fallen branches and debris. Winter storms and ice drop branches. Walk the property, clear them, and check for any larger limbs that are hanging or cracked but haven’t fallen yet. Those need to come down before they come down on their own.

Cut back dead perennial stems. If you left ornamental grasses and perennial stems standing through winter (which is good practice — they provide winter interest and bird habitat), now’s the time to cut them back to the ground before new growth emerges. Cut ornamental grasses to 4 to 6 inches. Cut dead perennial stems flush. Do this before mid-April or you risk cutting new shoots that are already coming up.

Inspect hardscape for frost heave. Walk your paver patios, walkways, and retaining walls. Freeze-thaw cycles can shift pavers, pop edging, and cause wall stones to move. Catch small problems now before they get bigger. A few shifted pavers can be reset in minutes. A leaning wall section needs attention before spring rains add water pressure.

Clean gutters and check downspouts. Winter debris fills gutters. Clogged gutters dump water against the foundation instead of routing it away. While you’re at it, make sure downspout drains are clear and pointing away from the house.

April — The Real Work Begins

When should I start mowing in Pittsburgh?

In most years, the first mow in the Pittsburgh area happens in early to mid-April. Grass starts active growth when soil temperatures reach about 55°F consistently — in the Pittsburgh metro, that’s typically the first or second week of April, though it varies by year.

Set your mower high for the first cut — 3.5 to 4 inches. A high first mow encourages root growth and shades out early weed seeds. Resist the urge to scalp the lawn short. Short-cut grass in early spring stresses the roots, invites crabgrass, and leads to a thinner lawn all summer.

When should I mulch in Pennsylvania?

Late April is the start of the mulching window. The soil needs to be warm enough that mulch won’t trap cold moisture against roots, but early enough that you suppress weed germination before it starts. In practice, that means once perennials are visibly emerging and the soil surface feels dry to the touch.

Apply 2 to 3 inches of hardwood mulch. More than 3 inches can suffocate roots and create moisture problems. Keep mulch a few inches away from the base of plants and at least 6 inches from tree trunks — mulch volcanoes (those cone-shaped piles against tree trunks) hold moisture against bark and cause rot.

Edge beds before mulching. A clean edge along the bed border keeps mulch from washing onto the lawn and gives the whole property a finished look. Bed edging takes time, but it’s one of those details that makes the difference between “maintained” and “sharp.” T&T Landscaping includes bed edging with every mulch and bed cleanup service.

What about pre-emergent weed control?

If crabgrass was a problem last year, a pre-emergent herbicide applied in mid-April prevents it from germinating. The timing window is narrow — you need to apply it before soil temperatures reach 55°F consistently for several days in a row, which is roughly the same week the forsythia blooms. Apply too late and the crabgrass has already germinated. Apply too early and the product breaks down before crabgrass season arrives.

Note: if you plan to overseed the lawn this spring, skip the pre-emergent. It prevents all seeds from germinating — including the grass seed you’re trying to grow. Overseed in fall instead, or accept the crabgrass trade-off for one season.

May — Planting, Fertilizing, and Growing

When should I plant shrubs and perennials in PA?

May is prime planting season. The soil is warm, the risk of hard frost is mostly past (Pittsburgh’s average last frost date is around May 10), and nurseries have their fullest selection. This is the month to install new shrubs, perennials, and trees.

If you’re doing foundation planting, border plantings, or adding to existing beds, here’s the general approach:

• Dig the hole twice as wide as the root ball, but no deeper. In clay soil, a wide hole gives roots room to spread into amended soil. Planting too deep buries the root flare and can kill the plant.
• Amend with compost. Mix the native clay with compost at roughly 50/50 in the planting hole. Blend the edges so you don’t create a bathtub effect where water pools in the amended soil.
• Water deeply at planting, then regularly for the first growing season. New plants need about 1 inch of water per week. That means supplemental watering during dry spells — don’t rely on rain alone in the first year.
• Mulch around (not against) the new plants. Two inches of mulch retains moisture and suppresses weeds around new plantings.

For a guide to which plants work best in the Pittsburgh area, see our Best Plants for Western PA article.

When should I fertilize the lawn in Pittsburgh?

The first lawn fertilizer application in western PA should go down in mid-to-late May — not April. Early spring fertilizing pushes blade growth at the expense of root development, which weakens the lawn heading into summer. A late-May application feeds the roots as they hit their peak growth phase.

Use a balanced slow-release fertilizer. Avoid anything labeled “weed and feed” — the herbicide component in those products often goes down at the wrong time for effective weed control and can damage desirable plants if it drifts into beds.

Spring pruning — what and when

Not everything should be pruned in spring. The general rule:

• Prune spring-blooming shrubs AFTER they flower. Azaleas, rhododendrons, forsythia, lilac, and bigleaf hydrangeas bloom on last year’s wood. Pruning them before they bloom cuts off the flower buds. Wait until flowers fade, then prune.
• Prune summer-blooming shrubs in late winter or early spring. Butterfly bush, panicle hydrangea, Rose of Sharon, and spirea bloom on new wood. Pruning them in March or early April encourages fresh growth that produces flowers.
• Shape evergreens in late May or early June. Wait until the new growth (the light-green “candles” on pines, the bright tips on yews and boxwoods) has extended, then trim to maintain shape. Cutting into old wood on most evergreens won’t regenerate — yews are the exception.

Late May and Beyond — Momentum

By late May, the Pittsburgh growing season is in full swing. The lawn needs weekly mowing. Beds should be mulched and edged. New plantings need watering. Spring-blooming shrubs are finishing their show and summer perennials are pushing up.

This is also the time to schedule hardscape work for summer. If you’re planning a paver patio, retaining wall, or new walkway, getting on a contractor’s schedule by late May gives you the best chance of summer installation. By July, most hardscape crews are booked weeks out.

Watch for problems early. Fungal diseases in the lawn (brown patch, dollar spot) tend to appear when warm days and cool, damp nights coincide — exactly the pattern Pittsburgh gets in late May and June. If you see irregular brown patches in an otherwise green lawn, that’s likely fungus, not drought. Address it before it spreads.

Weed pressure ramps up in late May too. If you skipped pre-emergent in April, you’ll start seeing crabgrass and other summer annuals. Hand-pulling is effective when the population is small. Once weeds take over, a professional lawn care program with targeted post-emergent treatments is more practical than fighting them by hand.

Need Help Getting Spring Started?

Spring landscaping in Pittsburgh isn’t complicated, but it is time-sensitive. The window between “too early” and “behind schedule” is narrow, and it’s different every year depending on the weather. T&T Landscaping handles spring yard cleanup, mulching and bed cleanup, planting, and lawn care across the 15108 area and greater Pittsburgh metro.

Call or text (412) 397-8004 or request a free estimate. We’ll get your property squared away so you can enjoy the season instead of spending every weekend catching up.