The May 2023 Garden Ramble

This week, as I run out of the days of May, a ramble — my monthly attempt to cover a number of topics briefly and sharing some information with you from other readers. There was a good deal of mail recently about my piece on lupines and my rant about pollinators. There’s more to come.

Of course we have to start with the weather. I was pleased to see that the East End, in many places, picked up an inch or so of rain last weekend. It’s still only the proverbial drop in the bucket as Long Island is still in the grips of the drought, though it’s not “severe.” Tell that to all the readers who have written to ask why their trees and shrubs have “suddenly” died.

For some there is no rhyme or reason as to why these plants died. However, when I begin to probe and ask questions there are all the clues that lead back to the drought and lack of water: Trees planted within the past two years that weren’t property mulched and only watered from time to time after planting. Some of the trees came from nurseries where the watering may have been touch and go.

The other big issue is when these trees and shrubs are planted. There’s a school of thought that has permeated the landscape industry that trees and shrubs should be planted in native soils with only a bare amount of amendments. This makes some sense when and where the planting is being done into deep organic soils like on the North Shore. Out here, where the soil is shallow and lacking in organic material like humus, the only way to have moisture retention in the newly establishing root zone is with added organics under and around the new planting.

Then how long do you water a new planting? For larger plants, tall trees or say very large rhododendrons and shrubs, I think two years. That means after the initial planting a good, slow soaking once a week when the soil isn’t frozen and cutting back to monthly, when possible, once the foliage drops. Remember, we once thought root growth stopped once the soil cooled off. That usually isn’t the case though, and if the ground doesn’t freeze hard, root growth can continue to some degree right through the winter.

If it seems like a daunting task there are tools to make it easier. There are a number of products that will water your trees and shrubs over a period of hours and days. Some are placed on the soil over the root ball or outward and look like large plastic doughnuts. Others can be hung from a limb or laid against the trunk, but the purpose and idea is the same. The water slowly drips or trickles down to the root zone and slightly outward providing moisture to the expanding roots.

If you were a client I would beg you not to get into a large landscaping project this year until there is good evidence that the drought is over. It’s a tough sell on the East End where money buys nearly everything. You don’t know how well the plant material you’re bringing in was cared for during the drought and when there is little to no rain it stresses the landscape as well as the landscapers.

If you are having trouble with your beech trees, American or European, you are not alone. In addition to a root disease and several other diseases these trees are now being hit with a new problem known as the beech nematode, which is also being called beech leaf disease. Use this link to find out about most of the current beech issues: dec.ny.gov/lands/120589.html.

I had hoped to cut back on my planting this year and thought I’d reduced my plant orders from previous years. Somehow the plants kept arriving though, and every day for two weeks there was a new box or two. When I thought the last box arrived last week I said to the FedEx driver, “That’s the last one,” and he laughed and responded, “Are you sure?”

But the drought up at my upstate garden is even worse than down here. I refuse to water my lawn as it always recovers but when one of my new perennial beds began to wilt en masse I had to water. That was a first. So what to do with all the new plants that have arrived? Planting them and keeping track of the watering would be a full time job so only a few will get planted and flagged so I remember where they are. The rest will go into larger pots and into a holding area where they are more easily watered and monitored. Some time before October they’ll all get planted.

Then there was the night of May 17th. I was in Manhattan but before I left from upstate I was aware that it was going to be a cold night. I covered my salad greens with Reemay and made sure all the new plants were under a tree canopy. On the East End it went down to the upper 30s. On my plot in the Catskills it was 25 degrees for several hours. I returned late the next day and saw no obvious signs of damage. The following day, however, was a very different story.

I was sitting in my office which has several large windows looking into the east gardens and the magnolia outside the window was looking strange. Keep in mind that it’s not uncommon, even in the Hamptons, to lose magnolia buds and flowers due to a late frost. This was a hard freeze though and every single leaf on this tree was crispy black. My heart sank as I began to walk the property looking for other damage.

Unfortunately, I found it. Astilbes, Hosta, Thalictrum and about a dozen other plants got toasted. I doubt if any were killed since it was an “air” freeze and not a soil freeze, but I need to inventory what was damaged for future protection.

Just a reminder: Climate change does mean the Earth is warming. It does not mean there can’t be an unseasonal arctic push of cold air. The nearby warm waters of the Gulf Stream do protect the Hamptons. But it only takes one arctic front with the winds out of the northwest to toast your plants as well.

My recent column on lupines and my ongoing comments on pollinators seem to have resulted in several responses. I am in no way supportive of wholesale abandonment of lawns either. The exception being those hidden behind the tall hedges where the fertilizer and pesticides are used to keep the carpets of green. These lawns are nothing but wholesale environmental pollution that kills our bays, the ocean and pollutes our drinking water. However, I feel so very strongly that this trendy push for turning lawns into meadows and the move to plant for pollinators is misguided, and I will continue to write about this.

Tovah Martin is a wonderful horticulturist and great garden writer. She also took one of my classes at the NY Botanical Gardens years ago and I never understood why. But she had a great piece in the Washington Post last week on turning your garden into a buffet for pollinators. It’s well written and full of great information so use this like to get it and by all means please read it: wapo.st/42QobW1.

If you’ve been sucked into the current houseplant craze and are new to these indoor tropical gardens you may be wondering about taking these plants outdoors for the summer. Please do it with care and consider the following: Houseplants can get sun burns just as we do. Never move a plant from an indoor location out into full sun even if that plant has been in “full sun” indoors. You can’t put sun screen on them but you can shade them and most should probably never go into full sunlight. Bright light, yes. Full sun, maybe not.

There is also the risk of picking up some insects (bugs if you must) that you will then bring back into the house and find it nearly impossible to control them. You won’t pick up scale or mealybugs just by bringing your plants outdoors. These two pests can only get on your plants if the plant is in physical contact with another plant that’s infected. Spider mites and aphids are another issue though and you need to be vigilant about these and knock them down as soon as they appear. Yes, both can simply be washed off with water sprays.

Keep in mind that insects aren’t the only issue. Slugs can enter a pot through the drainage holes and thrive in the pot soil as can a number of beetles. Slug baits and or diatomaceous earth are good management tools for these.

And while your plants are outside do they need repotting? Frequent wilting or the frequent need for watering is a good sign that it’s repotting time and June is a great month for this task. Take care of these plants and they’ll reward you for years. Keep growing.