Monday, August 07, 2017

Apiosporina morbosa - AKA Sh*t on a Stick

Please excuse the crudeness of Sh*t on a Stick, but that was the first coined term I was taught 25+ years ago. It stuck and I will never forget it. lol

It certainly depicts poop on a stick, doesn't it?  Apiosporina morbosa (even known as Dibotryon morbosum) is also called Black Knot. It is a rather noxious, pervasive fungus that attacks the prunus species of plants. Cherries, Plum, Chokecherry, Apricot, Almonds and ornamental cherry trees and shrubs fall victim to it.

This wet spring and rainy summer has made it more visible than ever. I usually see it more in the winter, when no leaves cover the knots.

Here, I found it on a Chokecherry tree. Matter of fact, I think every Chokecherry tree in the vicinity had it.

When the lesions first appear, they are much smaller. Just a callous and swelling bark - usually green-brownish-black in colour. Hardly noticeable at first, and only enveloping one side of the stem.  Each following growing season, the callous gall grows in diameter and becomes black and gnarly. Can get as long as 30cm. The knot is woody and will eventually encase the entire stem/branch. Eventually girdling the branch and causing die-back.  Once black, the infection has been around for about 2-3 years already. If there are several knotty turd like lesions on the tree, you'll definitely notice brach die back before you see the black knot.

 The Black Knot becomes active during warm, wet weather. "Ascospores" are forcibly released from the ascostromata of the fungus. On this sample, it had rained a lot overnight with strong winds. You can see the knot has white masses. Beginning a new life cycle on the blackened gall. Those white spots contain the acospores.  These spores are spread by air currents and rain splashing. 

When wet weather persists, the fungus acospores disperse and an injury or susceptible spot on the branch bark is like an open wound. The inoculum spores of the fungus invade the wound and start the whole process.  More Black Knot galls on the tree = eventual total die back = dead tree.

Treatment: Removal is key.

1) Remove during the dormant season. When the spores and tree are not active.

2) Cut back at least 10" below the knot. Better yet, if possible, remove the branch further back to a secondary stem, so that no stubby ends are left. Cut back to a collar or side shoot. Make the cuts on an angle so that no water sits on the newly cut area.

3) With EACH cut, disinfect your pruners/loppers. This prevents any contamination on newly cut ends and spreading it from host to new host.

4) Destroy the pruned branches. DO NOT COMPOST. Burn or discard in garbage. Black Knot can still release spores several months after being removed from the tree.


1) Stressed out trees are susceptible to Black Knot. Love on them a bit more. Water during drought periods. Mulch trees, accordingly.

2) Prune regularly. One of the biggest issues is overcrowded canopies. No air circulating between the branches or branches banging into each other, causes perfect conditions for the fungus to adhere and  spread throughout the tree.

3) Don't plant a Prunus species tree within a area close to a tree with Black Knot.

Here's proof:

At the base of this Chokecherry are visible signs that the tree had been suckering from the base. This is very common for older Chokecherry trees. A true sign of stress.

With TLC and extra monitoring, the Prunus species of trees can survive Black Knot.

Tuesday, July 18, 2017

Plant Profile: Calycanthus floridus / Carolina Allspice

There's nothing more enjoyable than spotting a beautiful, not so common shrub among the familiar.

Having visited the Toronto Botanical Gardens today, I had the privilege to take some photos of the grounds and I stumbled on one of my most favourite flowering shrubs: the Carolina Allspice.  Calycanthus floridus has such lovely, unique blooms which catch your eye and thankfully I came for a visit just when they were at their peak.

Rich, maroon red flowers that are held in tight buds to begin - reaching to at least 10 cm in diameter when fully opened. Depending on the light, sometimes the flower colours can range to dark pinks.

As the name suggests, allspice and or a strawberry like fragrance is emitted when smelling the flower and crushing the foliage.

In my experience, I've seen them grow to at least 8-10 feet tall and about the same in width. Growing both in full sun to quite a bit of shade. In shadier areas, they can get a bit leggy - stretching for what ever light they an reach.

Zone hardiness is between 5-9. Flowering time, between May-July. Yellow fall leaf colour. Great seed pods that provide winter interest and craft making opportunities. I used to play with the seeds which often smell a bit like red wine.

When we have brutal, harsh winters here in Toronto, they are known to die back some, but rebounding really well if they are situated in rich, loamy soils. In warmer climates, they can sucker and self-seed quite a bit. Easily remedied by pruning and removing the seed pods in August.

If I had the space, this would certainly be in my garden!

Saturday, July 08, 2017

DIY - Making Your Own Potting Soil for Herb Containers

If you want herbs to grow well in containers, then I can't stress it enough - making your own potting soil can't compare with store-bought bags.

The old adage: you are what you eat. It bears a lot of truth, especially when it comes to container planting. To have success, plants need to draw up water with nutrients and minerals. Most potting soils available on the market are soil-less mixtures. Peat mainly, with added vermiculite and or perlite. With soil-less mixtures, you will have to add synthetic or composted fertilizers to keep nutrients available to the roots, before several waterings will leach them out.  Ah, no thanks... I rather use more nutrient retaining soils.

In my experience, a mix of several elements is key. Herbs have significant properties we rely on and you want the plant to thrive and bear the flavours and medicinal goodness and flavours that we need. So why plant them in soil-less mixtures and expect good results? That just doesn't add up.

I compost. Not all kitchen scraps, but a LOT. Coffee grounds, veggie skins...egg shells, anything that will break down relatively quickly - for next year's batch. I also compost all my plant cuttings, autumn leaves and grass clippings. This makes a fabulous compost mixture that is fortified. But, I also balance other aspects too.

This is my potting soil recipe:

First: grab a wheel barrel or large vat (if you're lucky, you may even have a potting bench). Start by adding 1/3 compost, 1/4 sand, 2 cups perlite, 1/2 cup mycorrhizae for herbs and vegetables, and an 1/4 cup organic vegetable fertilizer. If you're like me, and plant herbs in a pot year to year, I reuse about 1/3 of the pot's original soil. Beneficial living organisms from the year before are still contained in there. You want to keep that cycle going by inviting them into the new mix.

Last year's old plant material. Removed all the roots, and dead bits, but kept half of the soil in the wheel barrel. NOTE: if you had diseases and problems with your planters last season, then DON'T reuse last year's soil. Begin with new soil.

This is how the various additives look:

Mix thoroughly together.

One key aspect of growing herbs, if you're going to plant several together, plant similar sun/hot to shade/moist selections together. I like planting "hot herbs" in terra cotta pots. Terra cotta pots heat up in the sun. You want a dry, Mediterranean conditions, and they will heat up if you keep the pots on hard landscaping surfaces.

Plastic pots work well to retain moisture and I use them for "cool herbs".

Here are some groupings that grow well together:

Hot/Dry:   Rosemary, Thyme, Sage, Oregano, Marjoram - these all like drying conditions and less waterings.

Cool/Part Sun: Basil, Chives, Parsley, Coriander - these all like moist conditions and can tolerate a bit of dappled shade.

With the hot/dry loving plants, you may want to even add more sand, to promote drainage.  The amount of sand may vary, depending on your compost. The more organic material that hasn't broken down, the more sand you will need. These hot plants hate roots standing in water.

Place pots in a sunny position. Place water trays beneath to catch water from leaching out too much fertilizer when you water.

Every 3rd watering I add compost tea that I make  (here's the link to that post) for an added boost.

Pinch segments back for your culinary needs and try not to let the plants bolt - meaning, not let them go to seed.

If you have noticed, I have several other little plants that have hitch-hiked their way into my soil. This year I had morning glories, tomatoes and bidens germinate from seed. Hey, why not! They add some colour and joy to this little spot by the kitchen entrance.


Wednesday, July 05, 2017

Helpful hint: Dahlias

Dahlias are at their peak now. I can't stress it enough - you MUST deadhead them to help keep them blooming. Keeping them from going to seed is quintessential but even more importantly...

...deadheading the old blooms prevents un-opened flower buds from getting any fungal infections.

With all this rain, sometimes the old flowers close up and leave wilted petals incased in the flower's sepals. This is a perfect place for moulds, and fungal spores to develop.

The smaller varieties like this one, you just pinch back with your fingers. With the dinner plate varieties, I would use a set of pruners or scissors to cut them back.

You can always easily tell which are the old flower seed head. When you pinch them, they are soft.

Enjoy endless blooms, with a good water soluble feed every two weeks: compost tea, fish emulsion or 10:52:10.

Thursday, June 15, 2017

Mild Winter = Bugs Every Where! Look Closely!

With this past mild winter, our wet early spring and now the heat and humidity; bugs are reproducing rapidly.

So far, I've seen aphid clusters by the thousands:

 Mealy Bugs:

Viburnum Beetles:

 Hydrangea Leaftier Moth Larvae:

Rose Plume Moth Larvae:

A positive note: whenever there are years of plague like proportions, remember there are natural controls, like this Lady Bug larvae feeding on aphids below. Please look carefully. Beneficial insects are in full force - fighting the good fight. Instead of using chemical sprays, use high pressure water controls, pruning techniques and boosting the health of the plant. Save beneficial insects like Lady Bugs and their larvae, as well as parasitic wasps, lacewings and the birds. We NEED them! Chemicals are not the answer.

We may complain about our harsh winters here in Ontario, but I welcome them. The severe cold kills many overwintering insect adults and eggs. And that, we need!

Sunday, May 14, 2017

Pet Peeve - Mulched Trees (aka the Coned Volcano)

So many new trees are going to be planted in the next few weeks.  I wonder how many will be mulched like this disaster:

This may be a harsh opinion, but it's warranted. Not only has the tree been planted too "proud" (meaning not level to the soil), but not only do we have the "cone" flared up mound, but we have red dyed mulch. Notice something else?  The plastic tree guard at the base of the tree is also nearly buried.

What happens to the tree trunk when mulch covers the bark?  Think about this comparison. What happens to your finger when you wear a bandaid wrapped around?  Your skin becomes soft, wrinkled and sometimes when you wear it a long time, the skin peels - right?  Well, the same thing happens to bark. Moisture, insects and possible mould will perpetually be in contact with the young bark tissue and possible suckers may develop.  Not what you need to establish a young tree.

Years later, the tree will continue to need mulch to cover this mound, like in the photos below.

To me the roots and the base of the tree would better be suited at grade - so that water can pool and collect during the heat of the odd summer shower. Snow melts quicker on these cone mounds.  Also the suns rays will bake the soil beneath quicker. Needless stresses; if only a proper planting and placement of mulch was achieved from the onset.

Below are better samples of tree plantings.

Here's why:

  • Using natural shredded bark mulch knits together. It suppresses weeds and keeps the roots cool - protecting them from the elements
  • Creating a crater in the middle ensures mulch doesn't touch the bark of the young tree

The mulch is spread to the width of the canopy of the newly planted tree. Granted, the tree will grow wider and thus the high edges (surplus) can be raked further out when the tree starts to branch out further. This is called the drip-line.

  • The crater not only helps keep the mulch away from the trunk, but when you fill a water bladder (the green bag) it helps to stabilize it. This is fantastic. If you are watering a tree on your own property, you can localize the water in the crater without it running off.
  • A lawn mower or string trimmer is unlikely to cause tree trunk damage when the tree is mulched well.

Here is a diagram resource as to how we are to mulch trees:
Diagram by: Arbor Day Foundation
Another resource:

Diagram by: Harvest Power
With all the info available, I still can't understand why mulching is still done in the volcano-cone style.

Please be aware,

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