1. Plant Health Care Products
As in from the company PHC, Inc.? Never used their products...
2. Mycorrizae
Yes, we have used it, and we like the results. Mycorrhizae can be depleted in urban soils as a result of the extreme edaphic conditions. In response, one can take a wheelbarrow of soil from a neighboring forest and thus innoculate the soil. Otherwise, you can purchase the products.
3. Root Collar excavation
All the time! You have to with the nursery and planting practices these days. Usually we perform this in conjunction with girdling root inspections (GRI). Sometimes, though, you simply need to peel back soil or mulch and the situation is rectified.
4. Vertical Mulching
We used to do it frequently, but the technique is no longer in vogue. Like JPS mentioned, radial trenching is the hip thing these days because of its drastically improved results.
5. Monitoring
It's 50% of our Spray/Inspection Program! The first thing I do, long before starting the sprayer, is to walk around the property, looking at all the plant materials. I wish with all my heart that I knew more about insect and disease problems, but I realize it's a long process.
6. Soaps and Oils
We've tried with good success to use organic and natural products when possible. One example of this is our use of DeerScoot to repel deer. The stuff is amazing! It's made of encapsulated hot peppers that will last for up to a month. Ummm... Seaweed-based fertilizers are the only ones we use. The nitrogen source is food-grade actually, the same material used in your favorite carbonated beverage.
Like Bob mentioned, it takes a premium price tag to make a true, complete PHC program possible. I'm not claiming that we've reached that point, but it certainly is a goal I wish to attain.
www.crawfordtree.com/services/si
Nickrosis