En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Sunday - June 09, 2013

From: Liberty Hill, TX
Region: Southwest
Topic: General Botany, Non-Natives, Compost and Mulch, Soils
Title: Problem With Vegetable Garden Soil
Answered by: Mike Tomme

QUESTION:

We live in Liberty Hill on 25 acres and we are working to restore native grasses and plants. We are ardent supporters of the Wildflower center. I say this because my question is not "typical" of what I follow. We have spent an inordinate amount of money putting in raised beds this year for veggies. The gourmet soil mix came from respected organic gurus. We planted in March-plants came up then atrophied. We replanted and now we have pale, emaciated "bonsai" plants. Soil tests show no nitrogen. We added manure, blood meal. The supplier does not believe us. Question: what could possibly make gourmet soil so toxic? Not one plant has grown.

ANSWER:

Normally, Mr. Smarty Plants doesn’t answer questions about vegetable gardening, but since you are an ardent supporter of the Wildflower Center, I’ll make an exception. Besides, I think I know the answer.

First let’s talk about your soil test. It is highly unlikely that your soil has “no nitrogen.” Was this a soil test from the AgriLife Extension Service or a home test kit?  If a home test kit, I highly recommend  you get  a “real” test done by AgriLife Extension.  I strongly suspect you have a nutrient imbalance and it is important that you find out where you stand with your soil.

However, I suspect that your problem lies with phosphorus rather than nitrogen. Commercial garden soil mixes typically contain a lot of compost which is high in phosphorus. The AgriLife Extension Service has a publication entitled Phosphorus: Too Much and Plants May Suffer. This is the opening paragraph of that publication:

“The buildup of phosphorus in lawns, gardens, pastures and croplands can cause plants to grow poorly and even die. Excessive soil phosphorus reduces the plant’s ability to take up required micronutrients, particularly iron and zinc, even when soil tests show there are adequate amounts of those nutrients in the soil.”

The report goes on to talk about corrective measures. I recommend you read the whole thing, but I’ll summarize the main steps:

1. Avoid future applications of phosphorus by eliminating organic composts and manures.

2. If nitrogen is required, use low phosphorus sources like blood meal.

3. Apply iron and zinc by foliar application.

The report goes on to discuss how long it will take to clear up the problem. Unfortunately, it will take years (3 to 5 years is their estimate).

I have personal experience with this problem. I built raised beds and blended my own soil, using lots of compost (no one ever told me you can use too much). My plants experienced problems almost exactly like you describe. I have been doing foliar applications of a solution of iron and zinc (available at many garden centers) and have been adding nitrogen to the soil (I use ammonium sulfate because my dog digs it up if I use blood meal). So far, it is working. My plants are much larger and more vigorous than before I started. But, if I get lazy and don’t do the foliar application on time, they start to droop and turn yellow. 

 

More Compost and Mulch Questions

Identification of shrub looking like honeysuckle in Odessa TX
October 02, 2011 - Bought a shrub in Pecos, TX yesterday. It looks like honeysuckle but the brightest flat orange I have ever seen. Flower and greenery looked like honeysuckle but when I looked on the Internet under or...
view the full question and answer

Lawn Maintenance in Colorado
March 20, 2010 - When do I begin to fertilize and water my grass in Colorado Springs? I am selling my house and want my lawn to look green?
view the full question and answer

Malpighia glabra for Austin
October 14, 2010 - Dear Mr. Smarty Pants, I am planting native Malpighia in a raised bed that was specially prepared for growing roses (soil and amendments). This bed has been left fallow for several years. Do I need t...
view the full question and answer

Native grass mix suitable for Houston
December 10, 2009 - Do you have a native grass mix that is appropriate to the Houston area- or will the one you have developed to this point work as well here as it does in Central Texas? If not, when will you begin to ...
view the full question and answer

Transplant shock in non-native crape myrtle from Wesley Chapel, FL
June 12, 2012 - I just bought a 12 ft. crape myrtle and planted it, giving it plenty of water I think. After 3 days the leaves are wilting and flowers are falling off.
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center