How to Choose the Right Fertilizer

#asmallorange Drew Caplan – At first these guys were great but a recent string of downtime, lack of support and flat out dishonesty led me to move away. Be warned, you will be let down by this company. Their uptime is terrible, chat waits times long and unhelpful and absolutely no phone support. They recently deleted all of the comments from their Facebook page to hide their unhappy customers.

Ask This Old House landscape contractor Roger Cook walks host Kevin O’Connor through the choices in fertilizers

CORRECTION: Roger misstates the functions of Potassium and Posphorous in this video. Potassium helps with chemical reactions and Phosphorous helps with root growth.

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Skill Level: Beginner

Shopping List:
Soil Test

1. A soil test will determine what nutrients are lacking in your soil and need to be augmented.
2. Follow all manufacturer’s instructions to ensure plants are overly fertilized and susceptible to burning.
3. The three main nutrients a plant needs are Nitrogen, Phosphorous, and Potassium, and these are noted as ratios on fertilizer containers.
4. Nitrogen-heavy fertilizers encourage green top growth on lawns.
5. Phosphorous-heavy fertilizers help with root growth (this is mis-stated in the video).
6. Potassium-heavy fertilizers help with chemical reactions (this is mis-stated in the video).
7. Liquid based fertilizers are good for establishing planters like a window box because they work quickly, then a granular slow-release fertilizer can be used over time.
8. Organic fertilizers have less nutrient density and are better for slow release applications like trees and shrubs.

Fertilizer can be found at garden centers or home centers.

Ask This Old House TV
Homeowners have a virtual truckload of questions for us on smaller projects, and we’re ready to answer. Ask This Old House solves the steady stream of home improvement problems faced by our viewers—and we make house calls! Ask This Old House features some familiar faces from This Old House, including Kevin O’Connor, general contractor Tom Silva, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook.
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Keywords: This Old House, How-to, home improvement, DIY, ask this old house, roger cook, kevin o’connor, fertilizer, lawn care, gardening, landscaping

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This Old House

  • Yashodhan Pasari
    Posted at 20:00h, 31 August


  • Samuel Lenting
    Posted at 20:01h, 31 August


  • Ken Custis
    Posted at 20:11h, 31 August

    When you have your soil tested, what will tell you which concentration of material you need to add?

  • cn 250
    Posted at 20:42h, 31 August

    Phosphorus ……that's why all of South Florida's canals are green with algae

  • Hank Dauley
    Posted at 21:17h, 31 August

    You're no using chemicals on you lawns

  • Josh B
    Posted at 21:28h, 31 August

    Milorganite, smells like success!

  • joseph Norcal USA #1
    Posted at 21:58h, 31 August

    helpful information, thank you for sharing !!!

  • Ireness 123
    Posted at 22:32h, 31 August

    These videos are getting less and less informative.

  • 68CamaroRS/SS
    Posted at 00:19h, 01 September

    I usually add Lime 3-5 times per spring-summer…fertilizer 2-3 times per spring-summer…sprinklers daily…don’t cut your grass too low and I have the best lawn on my street 👍….oh and I usually roll my lawn once every spring too

  • Withered Perception
    Posted at 00:51h, 01 September

    MILORGANITE 6-4-0 it's all you need to know! WON'T BURN!

  • All Eyez On Me
    Posted at 04:30h, 01 September

    Great vid. Always good to know, this kinds of things..

  • ncooty
    Posted at 10:57h, 01 September

    Great to see Raja back and looking healthy!

  • ncooty
    Posted at 11:03h, 01 September

    The focus on NPK is incomplete and a bit out-dated, now that we know much more about soil biology, the mechanisms that make nutrients available to plants. It's very inefficient, expensive, and irresponsible to try to overcome structural (e.g., compaction) or biological issues by adding fertilizers.

  • Palmer Hollister
    Posted at 13:14h, 01 September

    Any LCN fans here?

  • The Informative Trucker
    Posted at 15:34h, 01 September

    I thought the thumbnail was Potato chips lol

  • RetroSteve
    Posted at 19:11h, 01 September

    But i want something to make my grass grow slower but not kill it.

  • MikeBramm
    Posted at 23:35h, 01 September

    I've always used the phrase "Roots, Shoots, Flowers and Fruits". The first number means it will help the plant's roots grow. The second number helps with the shoots (or stems and leaves). The last number helps with the plant's flowers and/or fruits (or general help throughout the plant). Depending on what part of the plant needs help, select the fertilizer accordingly.

  • Jennifer D.
    Posted at 00:15h, 02 September

    Any thoughts on using "weed and feed"?

  • A Marmot
    Posted at 03:31h, 02 September

    Here in Anchorage I use 16 16 16 twice a year on my lawn (fescues and Kentucky Blue Grass). It works wonderfully.

  • Canelo, The Man, The Myth, TBE.
    Posted at 17:59h, 02 September

    What about pet friendly?