Expert: Kenneth Joergensen - 3/5/2005

Question
Hi Kenneth -

I live in NJ by the shore.  The soil in our area is acidic and sandy.  The soil drains quickly so it's usually very dry.  Black-eyed susans, purple coneflowers, gladioli and pine trees grow well around here.   Grass grows poorly.

Do you think that DUTCH Irises would grow in my area?  I can't seem to find info on what type of soil they like.

How about dahlias?

Thanks for your help!

Jill from NJ

Answer
If you live down the shore, you are most likely zone7a or 6b. We live in NJ,too, Middlesex county near New Brunswick and we are zone 6b. Dutch iris grow very well here, and good drainage (sandy soil) is actually preferred. Don't worry about soil acidicy. Most plants actually like it a bit acidic.

Plant the bulbs 3-4" deep and keep them well watered especially around the time they bloom. Avoid mixing too much compost or potting soil into the sandy loam.

Dahlias do very well, also, but they should not be planted until about last frost (say early May). Dig a hole 6-8" deep and mix the bottom 2-3" of the hole with compost/potting soil. Then place the tuber on the soil. Do not cover. When the sprouts are 1" out of the tuber, you can backfill with soil to which compost/potting soil has been mixed. After the sprouts are 6" above ground, add a layer of commercial fertilizer.

In late fall, after a first mild frost has blacked the dahlia foliage, cut the top of dahlias leaving 6". Then leave the bulbs in the ground for 2-3 weeks and harvest before a deep freeze. Store the bulbs dry and cool indoors over the winter.