Issue: September 14, 1998

To fertilize or not to fertilize new trees and shrubs


In the Spring of 1998 I planted a Blue Spruce, three Japanese Lilac Trees, two Hydrangea Trees and several Alberta Spruce shrubs. My questions is "Should I be fertilizing them this year or should I wait?" At what time of year should I fertilize and what type of fertilizer should I use? Thank you!


I don't recommend fertilizing newly planted trees the first year or two. It is important for root growth to predominate during this time. Fertilizers containing nitrogen will stimulate top growth at the expense of roots. If your soil is very sandy and low in nutrients, a light fertilization is appropriate, but only a light fertilization. The other components of fertilizer, phosphorus, potassium, and the minor nutrients will not cause problems, but the tree can probably wait a year or two for these as the quantities that they need are available in most soils. Again the exception is if you are planting into very sandy soils.

If you do need to fertilize with nitrogen, then next spring fertilize after growth has begun and is developing well. There is controversy regarding time to fertilize, but the answer that seems best is to fertilize after leaves have formed and are nearing full size.

Fall fertilization, after the tree is dormant, does make some sense. Just don't fertilize the tree in the last half of the summer since this stimulates growth when the tree should be maturing growth and preparing for winter.

You should contact your local Cooperative Extension Service office for details regarding your specific environment.

Starting a peach from a seed


What do I have to do to a peach pit to start a peach tree? I have surfed the web and can't figure it out. Please help.


A peach is a temperate zone tree and, as such, its seeds need a period of "chilling" before the seed can properly germinate and grow. They may grow without a chilling treatment, but the plant will do poorly and probably not survive.

This chilling treatment is also called "stratification." To stratify a seed, place it in a plastic bag with moist peat moss or vermiculite in the refrigerator (temperature near 40 degrees) for six to eight weeks. Following this treatment, the seeds may be planted outside or in a container and allowed to grow.

It is not necessary to split the pit and remove the seed. In fact, this often damages the seed. So, just stratify the seed in the refrigerator and then plant it.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email:, office: 505-865-7340, ext. 113.


For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!