DEAR JESSICA: I have a pear tree that's about 55 years old and have noticed what looks like grass ... EMAILER: Green masses growing on tree trunks or branches could be lichens, moss or algae.

For instance, what are those green masses growing on your trees? Those growths could be either lichens, moss or algae ... which is to say they like to grow on trees that are already ailing ...

The substance ... tree. – Multnomah County A: This look like a crustose lichen, which is not a pathogenic problem. It’s nothing to worry about. Our environment is favorable for many moss ...

A reader wants a column on what causes moss and how to get rid of it. I like the stuff and can’t get enough of it, but I will ...

Over the winter months in cold and damp weather, it’s common for algae, lichens and moss to develop. The substance is unsightly ... slabs are keep going green almost like mould?

Moss, which is a plant and not mould, grows as a result of poor drainage, and often in locations that are shaded by trees. It sprouts spores instead of seeds and can grow outwards, much like a carpet.

Ball moss does not kill trees. But as the small gray-green tufts become dense, they can shade developing buds. A small amount of ball moss is not harmful to a healthy tree. A heavy infestation in ...