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April 2021

Who was Karl Foerster?

By | Education, gardening, Species | No Comments

One stunning grass

I first learned about the Feather reed grass when I worked for the City of Coquitlam. My then gardener-boss was a fantastic teacher and, luckily, the gardens we maintained contained many Feather reed grasses.

Feather reed grass (Calamagrostis x acutiflora ‘Karl Foerster’) is a beautiful ornamental grass. I love the way the large seed heads sway in the wind; and I have one specimen in a pot on my humble patio. I rescued it from a work project which would have horrified Mr. Foerster; the grass that bears his name, unwanted!

Calamagrostis is a clump forming perennial grass, it’s hardy and fast growing. Its soft feathery green plumes mature into wheat-colored spikes. Poor Mr. Foerster would be horrified if he saw the way his grass gets machine gunned by landscapers in early fall into lifeless mounds. It’s as if the grass reminded them of wheat harvests. I leave my patio specimen alone and it’s totally fine.

Not too long ago, while reading a UK gardening magazine, I came across an obvious question: who was Karl Foerster? (See Blade Runner, The English Garden, March 2021, p.81) That’s what so fascinating about many plants: they have their own stories. But to get there, you must know the botanical name. Feather reed grass alone would never let you discover Karl Foerster. Always learn botanical names.

Who was Karl Foerster?

Karl Foerster (1874-1970) discovered the Feather reed grass hybrid species along a railway line in Germany in the 1930s. He ran his parents’ plant nursery which specialized in hardy perennials. He also lectured and wrote about hardy perennials.

He bred close to 370 crosses, mainly clumping grasses, Delphiniums and Phlox.

His key contributions to garden design were:

  1. popularizing the use of grasses
  2. using plants as the most important element in the garden
  3. seeing plants as individuals, not something to dispose of with the seasons

Check out these two beauties from my picture collection.

The specimen below looks great but I question its placement. At its best, the Feather reed grass covers up a laurel and obscures a sign. That’s all the excuse landscapers need to cut it down.

The grass is great but I question the placement.

Conclusion

I love grasses. They’re low maintenance and usually perennial; and they look awesome when they sway in gentle breezes. Thanks Karl!

Always learning about trees

By | Arborist Insights, Pruning | No Comments

Learning never stops

Learning never stops! Which is why I love the green industry and feel like I will never run out of topics to write about. Especially about trees. There is so much to learn.

Lee Valley

Take my shopping visit to Lee Valley as an example. I was there to buy new blades and springs for my Felcos ( Visit again on March 6, 2021, to read my Felco blog post). As soon as left my car, I noticed a cherry tree, planted in the middle of the sidewalk. Fungal fruiting bodies were screaming at me to notice them. And bang, as soon as I saw them, I knew the cherry tree was dead. That’s the rule. Fungus inside your tree is a disaster.

I love how the fungus-tree death connection automatically clicked in my head.

Healthy trees don’t sport fungal fruiting bodies.

Ray cells

Ray cells.

It pays to be connected to people on LinkedIn. I got this picture from a contact who marveled at seeing ray cells so clearly. Allegedly, ray cells are clearly seen in oaks.

Now, in keeping with the continuing education theme of this blog post, I went home and looked up ray cells on the internet. And I found out they’re pretty amazing.

The two main functions of ray cells in trees are:

  1. ray cells keep the growth rings together
  2. ray cells help shuttle water and nutrients in the xylem

They also look cool in cross-section.

Heading cuts

One of my private clients received a letter from her municipality, asking her to clear Japanese maple (Acer palmatum) branches off their city lamp. So they hired an arborist to do the jobs. And when I was on site to do finesse work (a nice way to say weeding), I took pictures of his heading cuts.

A heading cut.

Heading cuts are made to discourage main stem growth and promote side growth. In this case, we want to keep the maple from reaching the city lamp. The cut is made just above a branchlet or bud. And we can expect any new growth to happen sideways, not straight to the top.

Then I put my iPhone away and went back to weeding, mumbling something like “I could have made those cuts!”.

Never stop learning!

Tree topping disaster

By | Arborist Insights, Pruning | No Comments

Don’t do it!

Tree topping rules are straight forward: don’t do it! I was stunned recently at a site in White Rock, British Columbia, when I saw a topped Persian ironwood (Parottia persica) tree.

Persian ironwood trees are bulletproof. They don’t suffer from any diseases, the branches have interesting look and their fall color is spectacular. You can’t do much better when deciding on a landscape tree. But this owner had his own ideas; and it helped that he was the strata council president. That’s how it works. If you’re not on council, you won’t get approval.

If you’re feeling crowded, then take out the whole tree. But that’s very complicated nowadays because municipalities now care about tree canopy cover percentages. Unless your tree is dangerous, it’s difficult to get a removal permit.

I suspect, if the municipality knew about this tree topping, they might issue a ticket. It’s a nasty procedure. So nasty, I had to compose this blog post about it. So nasty, the International Society of Arboriculture (ISA) publishes a handout about tree topping.

Future growth

The tree will now push out new sprouts and the president will have to hack them down every year to keep the tree at the same height. If you don’t remove the sprouts, they will develop into poorly attached shoots.

Another drawback is that it no longer looks like a Persian ironwood tree while the other specimens nearby still look great. It’s a weird effect.

Trees also store food in their branches and heavy removal can cause serious shortages for the tree. They also need lots of leaves to produce food and topping removes huge chunks of the tree crown where leaves would have developed.

Also, large wounds like these may not heal and could potentially invite insects and diseases in. Generally speaking, three inch diameter is your rule. Any cut bigger than that, may be slow to heal.

With huge sections of the crown missing, the bark can also get injured by heavy sun exposure.

Conclusion

Don’t top your trees!