Ask Anna – Lichen & Rhubarb

Happy July everyone! This month we are answering two great questions!

This month’s first question is:

What is this stuff growing on my tree? Is it killing my tree?

That stuff is called Lichen, and it comes in many colours, including silver, green, orange, yellow or brown. Lichen can be flat or can protrude off the bark, and it can be found on rocks or even a car that has been parked for a very long time.

Lichen is using the tree as a support.

They need 3 things to become established: clean air, time and an undisturbed area. It’s an epiphyte, meaning it grows on another plant but is not parasitic, like an orchid growing on tree trunks in tropical rainforests. Lichens are a complex life form that is a symbiotic partnership of two separate organisms, a fungus and an algae. The dominant partner is the fungus, which gives the lichen the majority of its characteristics.

It’s a good sign and lichen can actually be of benefit. It’s a natural air quality indicator, as it absorbs everything in the environment around it, but only thrives when the air quality is clean. In fact, scientists use lichen as a measure of air quality in different areas.

Question #2: My rhubarb isn’t producing, any tips?

There are a few things you can do to increase your rhubarb production. If you see this flower pod or seed stalk starting to form, be sure to cut it at the base as soon as it shows up. The energy of the plant will go to making more leaves, thus extending the growing season.

A unique thing about the flower stalk is that it’s hollow. It needs plenty of moisture, but not sitting in water that it rots. Proper soil preparation is key before planting by adding organic matter like manure and loosening any compact soil. Allow 3 feet of space for it to grow. Fall is the perfect time to show the established plants like rhubarb some love.

Putting down some organic matter, like compost, in the fall will suppress some weeds and keep it nice and moist. Just put it around the crown of the rhubarb, not covering the plant.

If you would like me to answer one of your questions next month you can send your question to me at: [email protected] attention Ask Anna.

Be sure to stop by Harvest Market on the corner of Powerdam and Vincent Massey and say hi while looking through all the beautiful plants in the garden centre. I can guarantee that you will go home with a full trunk.

Also pick up your copy of The Cornwall Seeker and the Cornwall and SDG Snippets as you leave the store. They are in the rack on the left hand side of the Exit door.