Where To Go for Reliable Garden Answers

Getting good and accurate information on gardening questions and issues seems to be harder and harder despite our being well into the information age. The problem? Getting both accurate and good information.

From weed and bug information to what are the best plants to use — be they annuals, perennials, trees or shrubs — there is a wealth of information to be had and it’s at your fingertips or keyboard. But which is best and how do you know it’s accurate?

One of the best available resources is the Cornell Cooperative Extension. Each state has its own cooperative extension, and the function of local extension offices depends on the needs in the county or counties that the office serves. I grew up in Nassau County, and that’s where my first contact with extension people, then simply referred to as “agents,” was. When I was in my early 20s I moved out here and became involved with Cornell Cooperative Extension of Suffolk County, and as my career path changed several extension people took me under their wings and became my mentors.

The cooperative extension out here has specialists in home horticulture but there is also a research farm and lab in Riverhead where there are specialists in plant diseases, insects, turf, weeds and several other areas. These people are resources not just for me but for the master gardeners and staff at the home horticulture offices in downtown Riverhead as well as Long Island’s agribusinesses. Our extension office depends on several sources for funding and one of those sources is Suffolk County.

You can get access to incredible resources and references through the extension office and your journey should start here: ccesuffolk.org/gardening.

From this starting point you can gain access to diagnostic tools, advice and tons of reading and references. You can also learn how to get samples to the office in Riverhead, where the insect and disease identification process usually begins. You can also make contact over the phone and online; just check out the site.

Now remember how I said in the beginning that you need to take advice with a grain of salt? Well not all extension offices are created the same. And while I think we have the very best, I recently became aware of an instance that made me appreciate our extension office even more.

A friend was having trouble with boxwoods at their upstate second home. They brought me a sample, and under a microscope it was very obvious that two of the main issues were rampant mites and a leaf hopper-like insect called a Psyllid. Both insects pierce the leaf surface to feed on the leaves, leaving yellowing, stippling and a general decline of the plant that was all quite visible under a microscope. I suggested, however, that they take a sample to the local extension office for a better look. They did.

At the upstate office a woman there gave them advise without even looking at the sample. She opined that it was a fungus problem and the plants should be sprayed with a copper fungicide. That was it. Even a quick look with a small 10x jewelers loupe would have revealed the mites and Psyllid, but the sample never came out of the bag. The woman’s response was so utterly contrary to how trained extension staff is thought to diagnose problems. It was shocking, seemingly wrong and not the way extension usually works. They tend to be very conservative, and I’ve never, ever met extension-trained personnel, even volunteer Master Gardeners, who would make a recommendation without carefully examining a sample and asking several questions. This would never happen in Riverhead, and I still believe that Cornell Cooperative Extension offices are one of our very best resources.

The next big question is how do we find out about new plant introductions or evaluations of plants and how they perform in science-based trials? For example, there are now scores of Echinacea varieties available and some are stellar while others are not. Some are great for pollinators and others are useless. We’re just at the tail end of Hydrangea madness with more varieties showing up at garden centers every year. The claims are that they are better or improved. But who’s telling us this? The growers and retailers of course but with a bit of homework you can find research-based information that is not biased.

At meetings and conventions of growers, garden writers and horticulture promoters I’ve been pleading for years for factual, science-based information on the plants that we buy. One owner of a tree and shrub nursery in Maryland responded to me, “Well, I grow all this stuff at home, and it does just fine.” Hmm, not quite what I’m looking for as he won’t tell us about failures and issues, only what “does just fine” while the rest of the garbage still ends up where we buy it on the retail end.

Proven Winners, one of the better brand names, does claim to do evaluations and trials. However, if these are in-house trials by their staff and growers it really can’t be thought to be independently verified. It’s great to read about and wonderful that they are doing this, but I really, really depend on independent evaluations by those who don’t stand to gain or lose based on the results.

Proven Winners seems to have taken trialing to heart though. One of their current campaigns says in bold letters “Trialed and Tested.” For a number of years they’ve sent me plants to trial. I only mention the great ones, and I always try to put one in a garden and another in the trial area where plants are simply lined out.

This new, shall we say, “awareness” may have resulted from some of their early Hydrangea introductions that were touted as being hardy in zones where they were not and said to bloom in zones where they never bloomed. I still have a few of these from my trials of over 10 years ago. Some return every year and yet several of them, in spite of having been moved to “better” locations still fail to bloom. But again, Proven Winners is a great brand and at this point in time I have full faith in their offerings.

Friends can also be a great source of information on successful plants, but again, with a grain of salt. Locally I think an organization and the members of a group like the Horticultural Alliance of the Hamptons can also be a great resource. Landscape architects, on the other hand, often have little direct experience with the plants they specify and I’ve found this to be an issue from time to time. On the other hand, if you use a landscape or garden designer who actually works with the plants and has first-hand knowledge of them he or she would be a more reliable resource.

Garden center staff that is well trained and with years of experience can also be helpful but shy away from the staffer who is seasonal and has little real-world experience. Home Depot and Lowes are not repositories for great advice and information. On the other hand, places like Marders and Fowler’s can often be gold mines.

Next week, tapping into the science-based information, trials and information that can make your plant purchases successful and reliable. These resources will give you information that you otherwise might never see or hear about. Keep growing.

Garden Notes

Spider mites (and other mites) are doing a job on a number of shrubs this year. Readers have noted them on boxwoods and on privet. While there may be other insects present, this seems to be another banner year for mites. Mites are usually hard to spot without a magnifying loupe (10x) or a microscope, but their damage is often obvious. They use their needle-like mouthparts and insert them into cells and suck out the liquid. This leaves behind a tiny yellow spot, and we refer to this spotting as stippling.

The mites can be managed with neem oil and other horticultural oils. An arborist may want to use another oil like a light summer oil and that works as well. The neem (only the cold-pressed type), however, has some mild residual effects and is organic. Repeated applications will be necessary, then next spring make an early application or two at the appropriate time. Be wary of arborists and landscapers who want to apply imidocarb (Merit) as this is a strong poison that sticks around and may show up in our groundwater supplies.

If you’ve had a good deal of digitalis in your garden and you want to reduce its return next year then cut back the flower stalks to the last flower as the stalk fades. This will result in several smaller shoots to emerge that will flower later in the summer and into the fall. Have your fall vegetable planned? It’s time to start some planting.

And speaking of trials, last year I planted two new Shasta daisies (Leucanthemum). One is “Banana Cream II” and the other “Spoonful of Sugar. “Not only did they overwinter in fine shape, but both are covered with flowers that are plentiful and dense and the plants have remained fairly tight and compact. Very nice compared to the older varieties of Shastas that can got leggy and sloppy. So far, both highly recommended.