Q. Our vitex has done well for over 20 years but it is starting to thin out. What gives?Vitex or Monk's Pepper tree is mesic in its water use. Similar to oleander, it prefers to grow under mesic conditions (can handle a lawn for instance) but can also handles dry soil, to an extent. It prefers a fruit tree water environment so it can handle a  well-drained lawn. A. Hard to get blue flowers ..read more

Q. Can ‘Interlaken’ grapes take eastern, southern or western exposure?  What about blackberries?'Thompson Seedless' dessert grape. Sorry, no pictures of 'Interlaken' but similar.Blackberries popping up through the mulch, after removal, where ever there is irrigation. Could be 'Womak' or possibly 'Rosborough' two varieties I would recommend for our climate. A. Both grapes and blackberries should ..read more

Q. A neighbor suggested we look closely at Australian racer. It stays low and is green. Seeing it in place, we like it. What are your thoughts about it?Myoporum, or Australian Racer as it is known by local nurseries, was a ground cover substitute. As it got larger it would frequently die in the center after a few years. Its major problems are spider mites and root rot from watering it too often ..read more

           Roots of plants do not grow separately. They grow together, all mixed up. Roots search for open spaces that are wet. They use the water for irrigated neighboring plants. Before now, we used to assess all the different plants’ water use and then add them together. Collectively they made up water needed by a landscape. But now, because we can’t separate the roots, we estimate the water ..read more

Q. I see online some people cut the roots of asparagus before planting. I did this last year. Is it a good idea? I was thinking of planting asparagus at the base of fruit trees. It makes them easier to plant, but are there consequences?Asparagus can get 5 feet tall or taller after harvest. A. Your question is about cutting the roots of asparagus and what consequences might occur. I must guess ..read more

Q. This may be a bit too amateurish for your column, but I need help with 'Iceberg' roses. I pulled the rock away and fertilized this past spring. I thought the roses I planted in pots would do better, but they don’t.  I ask the nurseries when I go but get conflicting information. Why are there holes in the flowers?  When I see dark leaves that look diseased, I pull them off.  When I deadhead and ..read more

Q. You posted pictures about watering with the depth of a plants root system. How do trees survive in lawns then?Suggested root depth of different plants and how much water to give them. This makes it easier to see that taller plants have deeper roots and need to be watered as such. As the roots get deeper they also get wider. This is why big trees use more water than little trees.  https ..read more

Q. I have some snails in my lawn. How do I get rid of them?Snails like it wet and darker than most lawns. A. The best way to control snails (or slugs) in lawns is to give the lawn more light. Snails hate light but they like to eat!  Snails and slugs eat young plants and microscopic plants such as “large enough to see” algae. The worst situation for snails and slugs is lawns growing under trees ..read more

Q. I was in Moab, Utah, when I ran across this apricot tree. It’s doing very well. I'm guessing the reason they are doing so well is because of the high organic levels in the soil and cooler temperatures?Temperate fruit trees like apricot, peach, nectarine, plum and apple prefer cooler weather that elevation provides, organics in the soil, and watering like any other mesic tree. A. You're right ..read more

Q. A local tree guide does not recommend planting Japanese blueberry because of “environmental challenges”. We had one at our old house and it was fine. It is the right size and shape for a spot we are considering.Young Japanese blueberry. It does not like the heat and isolation in Las Vegas landscapes. It prefers to be on the north or east sides of a home and surrounded by other plants that need ..read more