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Photo: N/A, License: N/A, Created: 2017:10:28 11:47:10

William Arp clambering at boulder field.

Somehow I recently ended up at a timeshare sales presentation in the Poconos. One of the perks offered was “country-club access” to all of the resort’s amenities. And, if we decided not to buy the timeshare offering, we could still buy just the “country-club access.” Almost as quickly as you can say “Hickory Run State Park,” we were at the boulder field using a “priceless” country club membership that we access too infrequently, even without our schedules being filled with a pricey resort-country-club perk.

If you have not been to the boulder field, which is registered as a National Natural Landmark, I hate to spoil the surprise by describing it. (On our way there, we refused to show pictures to our son William or even tell him what the field looked like. When he got there, he was glad for the surprise). The boulder field looks like the smaller half of the lake at Lackawanna State Park, but this ten-foot-deep “lake” is composed of boulders, most of which you could not lift. The lake has a forest completely surrounding its shore, and there are even a couple of islands.

Among its many mysteries, the boulder field has at least two landscape lessons to teach us.

First, “weeds” will grow in anything. Several weeks ago I did a landscape consultation for a friend. For convenience he wanted to eliminate his front lawn by spreading a plastic or fabric weed barrier and then covering it with gravel. I explained to him that no matter how deep the gravel or how impermeable the barrier, weeds will eventually grow.

The stewards of the boulder field are concerned that the field is shrinking, and this is obvious along the shore. Even though the “gravel” are huge boulders ten feet deep, organic litter from the forest is creating soil among the boulders, and plants are beginning to grow. These plants, of course, will add additional soil-creating litter of their own. But they must have forgotten to put a permanent plastic weed barrier under the boulders.

The second landscape lesson teaches us about aeration. While there are many remaining mysteries about the boulder field, there appears to be consensus about where the boulders came from. During the ice age, the area was not covered by the ice sheet, but was nonetheless subject to permafrost. Water infiltrated tiny cracks in the bedrock and the freeze-thaw cycle both broke up the boulders and lifted them to the surface. Once at the surface, water under these school-bus sized rocks can reportedly lift them to a height of two inches. It is this same freeze-thaw cycle, that we must embrace as a means for getting air to the roots of our plants. Take care of the worms by whose tunnels water can enter your soil and begin its freeze-thaw aeration.

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Joshua Arp is an ISA-certified municipal specialist, Clarks Summit’s municipal arborist and an operator of an organic lawn and landscape maintenance business.