Pennsylvania has new rules on when and how you can fertilize home lawns.

Pennsylvania has a new set of rules aimed at preventing unnecessary lawn fertilizers from polluting waterways.

Signed into law by Gov. Tom Wolf July 11, the bipartisan legislation regulates what fertilizers can be used on lawns, in what amounts, and when.

The rules apply to homeowners fertilizing their own lawns as well as lawn-care companies and professionals fertilizing park lawns, golf courses, and athletic fields.

For starters, the new rules prohibit the application of any nitrogen- or phosphorus-containing lawn fertilizer between Dec. 15 and March 1 … or any other time the ground is frozen to a depth of at least two inches or when snow-covered.

Lawn fertilizer containing phosphorus is prohibited altogether, unless a soil test or other specific documentation shows that the lawn needs it. Most lawn fertilizers already have dropped phosphorus as an ingredient since most soils have enough of this nutrient to adequately grow grass.

Three other exceptions allow phosphorus: 1.) when a new lawn is being established; 2.) when a lawn is being repaired; and 3.) when the phosphorus is in an “enhanced-efficiency” product or in a natural organic or organic-based fertilizer.

Phosphorus rates are capped at a quarter-pound of phosphorus per 1,000 square feet of application with a maximum total annual application of twice that.

The rules also limit amounts of nitrogen that can be applied. Nitrogen is the main nutrient in lawn fertilizers and the one most responsible for dense growth and green color.

Under the rules, nitrogen can’t exceed seven-tenths of a pound of readily available nitrogen per 1,000 square feet (i.e. “fast-release” or water-soluble nitrogen) and can’t exceed nine-tenths of a pound of total nitrogen per 1,000 square feet.

Enhanced-efficiency or “slow-release” nitrogen fertilizers are exempted from the totals so long as the amount of nitrogen released at any given time doesn’t exceed seven-tenths of a pound per 1,000 square feet of application.

As with phosphorus, there’s also an exemption on nitrogen limits when the applicator can show that more is necessary.

Three other rules in the new law:

Lawn-fertilizer regulation has been in the works in Pennsylvania for 12 years. The result is similar to legislation that’s been in effect in Maryland and Virginia since 2011.

The U.S. Environmental Protection Agency has been encouraging states to develop ways to keep nutrient pollution out of waterways, where it leads to excess algae blooms that create “dead zones” in key bodies of water such as the Chesapeake Bay.

Lawns are one source of nutrient pollution (estimated at about 14 percent of the total) that occurs when unused nitrogen and phosphorus leaches or is washed by rain into streams and beyond.

The penalty for a first violation of the new lawn-fertilizer rules ranges from $50 to $100.

These tree leaves are scorching around the edges from prolonged summer heat and dry soil.

It’s been a rough July this year for trees – especially young ones.

Intense heat can take a toll in several ways, leading to damage that’s sometimes immediate and obvious (scorched leaves and dead branch tips, for example) but also sometimes more subtle and gradual.

Temperatures in the 90s slows tree growth and shuts down the photosynthesis process by which trees make and store energy. They’ll usually recover from short bouts of high heat, but the longer the heat lasts and the higher the heat goes, the more the energy deficit grows.

Several years running of high heat can cause enough cumulative deficit that one year the tree dies – usually in spring (ironically not in summer) because the new season’s growth demands kick into high gear then and can’t be met due to a lack of energy reserves in the roots. That’s when the whole plant “suddenly” shuts down.

Heat also drives up a tree’s water demands. When rain isn’t happening to compensate, the tree first tries to defend itself by wilting or curling its leaves (reducing surface area where water transpires out), then by shedding its leaves or needles altogether if things get really bad.

Trees also might go into a dormant or semi-dormant state in an attempt to conserve energy and survive.

Depending on the species and age of the plant, death is the next step beyond that if weeks of stress drag on.

Trees that are adapted to hot climates (bald cypress, ginkgo, Eastern red cedar, and hawthorn, for example) are better able to deal with summer heat waves than species native to cooler climates (such as sugar maple, aspen, Norway spruce, and gray birch).

Young trees also are more at risk of heat and drought injury than mature trees because they have much smaller root systems.

So what can you do to help your trees through the rest of summer?

Water is most important. It not only supplies moisture to the roots but cools the air around trees.

Pay special attention to trees that are only a few years old. These usually benefit from at least one deep soaking a week in summer. Two a week is better.

Established trees can go weeks without water but also benefit from deep soakings when dry heat drags on, especially if the leaves are showing early signs of drought stress, such as wilting or browning around the edges.

In both cases, apply enough water so the soil is damp six to 12 inches deep and out to at least the edge of the leaf canopy.

A second safeguard is making sure the ground under and around the tree is covered either with plants or with two or three inches of organic mulch. This shades the soil and results in less moisture loss than bare soil.

It’s fine to mulch now. Mulching isn’t just a spring thing.

A third aid is avoiding pruning.

Pruning increases moisture loss through the openings and diverts energy into healing.

And fourth, don’t fertilize during a hot, dry spell.

Fertilizers often contain salts that increase the drying effect in soil.

Also, fertilizer aims to stimulate growth, and that isn’t needed at a time when a tree is attempting to survive, not grow.

This aphid infestation on a milkweed plant might look bad, but it might actually be helpful to monarch butterflies.

Lots of gardeners are trying to grow milkweeds these days in an effort to boost the hurting population of monarch butterflies. Monarchs lay their eggs exclusively on milkweed species.

However, many a first-time milkweed gardener is aghast this time of year when two different bugs swarm on milkweeds to seemingly threaten the food of monarch caterpillars.

One bug is the oleander aphid, a non-native, yellow to yellow-orange, little pear-shaped crawler that clusters on milkweed leaves, stems, and pods.

The other is the milkweed bug, an orange and black bug that’s similar in size and coloring to what people commonly called “lightning bugs” (the ones that fly and light up after dark).

Although the infestations look bad, this is a textbook case of why it’s not necessary to kill anything and everything seen congregating on a plant.

Neither of these bugs pose serious threats to milkweed survival, and there’s even evidence that the aphids benefit milkweed caterpillars.

A study done by Penn State entomologist Dr. Jared Ali while at Michigan State University found that monarch caterpillars feeding on milkweeds that also were infested with aphids weighed 37 percent more than caterpillars feeding on plants without aphids.

The aphids’ presence also had no impact on the amount of leaf feeding being done by the monarch caterpillars, suggesting that the aphids are doing their thing while the caterpillars are doing theirs.

The bottom line is that if you can overlook the cosmetic damage being done by aphids and milkweed bugs, there’s no need to spray or take any action.

The conundrum is that if you use sprays or other measures to control the “pest” bugs, you risk killing monarch caterpillars as well.

If you really feel the need to do something anyway, the least harmful tactic is to squish or remove the aphids and milkweed bugs by hand. It’s also possible to gently vacuum them off or to knock them off with a spray of hose water without doing too much monarch damage.

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