Here are three helpful tips for autumn, courtesy of the free newsletter from Heimiller Greenhouses.
Tip #1: How to deal with tar spot
When it comes to tar spot, there’s bad news and good news and more bad news.
The bad news is that tar spot is an ugly black fungus that seems to infect Norway maples, to a greater or lesser degree, every year, according to Lisa Heimiller of Heimiller Greenhouses.
The good news is that while tar spot is ugly, it rarely compromises a tree’s health.
The bad news is that it’s hard to get rid of.
In order to eliminate tar spot, you have to remove every last leaf that falls to the ground, Lisa said. Get rid of the leaves offsite or compost them far away from your maples.
Of course, in order for this to be truly effective, you also have to take care of all of your neighbors’ leaves in the same manner.
Here’s why: In the spring, those black spots will produce fungal spores that, if they are allowed to become airborne, will re-infect the tree and those around it.
The overplanting of Norway maples as street trees in the past means the fungus is pretty much everywhere. The best advice, she said, might be to wait until you must remove a Norway maple, then plant something else in its place.
Tip #2: Prepare a spot now where you can plant peas in spring
It’s possible to plant peas (and sweet peas) as early as the end of March or beginning of April– if your soil is ready, said Ron Heimiller.
If you prepare your soil now, you’ll be ahead of the game.
First, choose the highest spot you have so that your soil will be as dry as possible in spring.
Next, remove the weeds and break up the lumps in the soil. Working the soil now will help it dry out more quickly in the spring because it will be looser.
If you want to add peat moss to your soil, Ron recommends waiting until spring.
While it’s possible to plant peas as early as the end of March, you have to go by your soil conditions, not the calendar, he said. This year, the soil was much too wet and you wouldn’t have been able to plant them that early.
In the spring, you don’t want to work the soil when it’s too wet. If you do, it will be hard as a rock when it dries out.
You can plant peas as late as May; you just won’t get as much of a yield if you have to plant later, he explained.
Tip #3: An easy way to plant tulips
The Heimillers passed along this tip from Cornell University.
A Cornell study shows that a much easier method of planting tulip bulbs is just as effective as digging the traditional 6- to 8-inch holes for each bulb.
All you have to do is loosen the soil two inches down, place the bulbs on top of the loose soil, then cover the bulbs with an additional 2-4 inches of mulch. No strenuous digging is needed.
This method hasn’t been tested on other bulbs, but William B. Miller, professor of horticulture and director of Cornell’s Flower Bulb Research Program, thinks it would work with any bulbs.
You can plant spring bulbs anytime before the ground is frozen. Miller said bulbs root readily as long as soil temperatures are in the range of 40-50 degrees Fahrenheit.
“Plant them even into December,” Miller said. “Really, anytime until the ground freezes. In other words, late planting is better than not planting!”
4 Comments on “Dealing with tar spot, plus two other timely tips for fall”
Thank you for your reply. EAB is relatively new to our area, so it will be interesting to see in what direction management proceeds and how affected we become locally with culling ash, if it leads to that as it has elsewhere.
Thanks so much for your reply. You’ve expanded the discussion and added helpful information.
For our readers who might not be familiar with the abbreviations, EAB is emerald ash borer, IPM is Integrated Pests Management and the Extension is Cornell Cooperative Extension.
Hi there! I’ll field this, as I originally wrote the piece.
You are 100% right – tar spot – or any fungus (or disease or bug) – will be opportunistic and attack trees that already are weak. I think that’s one of the reasons it’s been tough to tell what is ash decline and what is the EAB (purely my speculation). But I am not the expert on these matters. For IPM questions I always consult Brian Eshenaur, who works for the state IPM program, or, of course, Extension.
As per tar spot, we have 80 foot high Norway’s on our street that are about 90 years old. And within the last ten years have suffered excessively from tar spot. This is due to the declining health of the trees. A healthy tree should less susceptible, weather conditions permitting. The trees have the oddly defined Maple Decline, complicating the health of the trees. Being street trees, poorly located, and constantly damaged, it is not any wonder why they are affected repeatedly. I do believe a compromised tree may suffer from tar spot to some extent because having less foliage to begin with, it is less able to photosynthesize. Maybe Miss Heimiller can further elaborate with any additional comments.