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Fertilizer for Lilacs #789488

Asked May 05, 2022, 5:18 PM EDT

Hi. Apparently, our lilacs were hit hard from the drought and are in need of some fertilizer. The Arborist would like to charge $400 for Essential Plus application now to give the lilacs some strength before pruning. Do you have a recommendation for a fertilizer we can apply ourselves? I believe the fertilizer should not contain nitrogen. Please advise.

Washington County Minnesota

Expert Response

Thank you for writing.
Lilacs are durable and not fancy.
A once a season slow release should be more than adequate.  You definitely ill not need phosphorus--it is ample in the soil.  A NPK of about (5-10)-0-(5-10) will be fine.
The Master Gardener Program does not recommend specific commercial products. 
Steve Miles, Master Gardener, Hennepin County, (I am a volunteer human being: not a bot, not AI). I'm an avid gardener but not a degreed or certified horticulturist or arborist. I will do much better if you also send a photograph. I like follow-up questions.  The University' garden soil tests are excellent.  https://soiltest.cfans.umn.edu/testing-services/lawn-garden This is how to find a tree expert.  https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional  A Directory of ISA certified arborists is at https://certificates.directory.isa-arbor.com/  The Minnesota Landscape Arboretum is a wonderful place to see and learn about plants that grow in Minnesota. https://mngardens.horticulture.umn.edu/minnesota-landscape-arboretum  Ask a Master Gardener is a public service of the University of MInnesota's Extension Division.  Please donate if we make you happy.  https://give.umn.edu/gardener Replied May 05, 2022, 6:26 PM EDT

HI.  “Lilacs are durable and not fancy.” – Perfect description LOL

 

The insanely expensive Arborist said the Lilacs do not need Nitrogen.  You said no to Phosphorus.  I trust you. Please clarify aka dummy down this sentence “A NPK of about (5-10)-0-(5-10) will be fine.”

 

Thank you kindly,

Jessie

 

Sent from Mail for Windows

 

From: Ask Extension
Sent: Thursday, May 5, 2022 5:26 PM
To: Kelleyjessie
Subject: Re: Fertilizer for Lilacs (#0059419)

 

The Question Asker Replied May 06, 2022, 11:56 AM EDT
Thank you for writing back
All fertilizers are labeled NPK for the amount of Nitrogen, Phosphorus, and Potassium.  https://extension.umn.edu/manage-soil-nutrients/quick-guide-fertilizing-plants
In your case, the number I gave was for a liquid, you can go higher for slow release pellets because the fertilizer gets into the ground more gradually. In my gardens, I use slow release once a year.  
Steve Miles, Master Gardener, Hennepin County, (I am a volunteer human being: not a bot, not AI). I'm an avid gardener but not a degreed or certified horticulturist or arborist. I will do much better if you also send a photograph. I like follow-up questions.  The University' garden soil tests are excellent.  https://soiltest.cfans.umn.edu/testing-services/lawn-garden This is how to find a tree expert.  https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional  A Directory of ISA certified arborists is at https://certificates.directory.isa-arbor.com/  The Minnesota Landscape Arboretum is a wonderful place to see and learn about plants that grow in Minnesota. https://mngardens.horticulture.umn.edu/minnesota-landscape-arboretum  Ask a Master Gardener is a public service of the University of MInnesota's Extension Division.  Please donate if we make you happy.  https://give.umn.edu/gardener Replied May 06, 2022, 2:41 PM EDT

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