The best fertilizers for container gardening.

Organic fertilizers for container gardening: The best choices for success

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When it comes to organic fertilizers for container gardening, you have two basic choices: granular or liquid. Let’s talk about each of them in detail. 

This post is an excerpt from Container Gardening Complete by Jessica Walliser

Complete Granular Fertilizers for Container Gardening

There are dozens of different brands of complete granular fertilizer blends. Most of these products combine assorted plant, manure, animal, and mineral-based ingredients, and depending on the brand, they may have an N-P-K ratio of 4-5-4 or 3-3-3 or something similar. What makes them “complete” is that they contain a combination of ingredients that provides some amount of all three macronutrients (nitrogen, phosphorus, and potassium), in addition to many trace nutrients, vitamins, and other things. All of these products have different formulations and compositions, so be sure to chose appropriately according to what plants you’re growing in your container garden. Some complete granular fertilizer blends are even tailored for specific crops, such as tomatoes or flowers or bulbs, and are labeled as such.

Fertilizer spikes are a great way to fertilize container gardens.

Fertilizer spikes are an easy way to add fertilizer to your container garden. These compressed granular fertilizers are formulated especially for tomatoes, peppers, and other fruiting crops and are pushed down into the soil around the base of the plant.

For the best results, add granular fertilizer to your containers according to the label instructions. Many gardeners find they get the best results by fertilizing their containers with granular fertilizers two or three times throughout the growing season.

With granular products, it’s possible to have too much of a good thing. Even natural fertilizers can be easily over-applied, leading to several different issues, including nutrient deficiencies, pH imbalance, and/or fertilizer “burn” (yes, even some natural fertilizers are capable of this). To avoid these issues, don’t overdo it by applying too much, too often. Again, be careful to follow all label instructions.

Liquid Organic Fertilizers for Container Gardening

Liquid fertilizer products are absorbed into plants via both their roots and their foliage. In general, nutrients provided to plants via a liquid solution are more readily and rapidly available for plant use. Like all fertilizers, water soluble ones provide plants with some of the necessary nutrients for increasing yields and improving growth and vigor, but not all liquid fertilizers are created equal.

While chemical-based, water soluble fertilizers certainly supply plants with the macronutrients specified on the label, these products are made from salts that can harm beneficial soil organisms. Instead of chemical salt-based fertilizers, look for organic or natural-based liquids which can reduce the risk of fertilizer burn and offer a more balanced “diet” for your plants. In addition to the three macronutrients, most natural liquid fertilizers for containers also contain dozens of trace nutrients, vitamins, amino acids, and plant hormones, each of which plays a vital role in the health and vigor of a plant.

Liquid fertilizers for container gardening are often the easiest to use.

Natural liquid fertilizers are absorbed into plants through both their roots and their foliage. They’re easy to use and filled with trace nutrients. Mixing liquid fertilizers in a watering can is the simplest way to apply them.

There are many different types of liquid fertilizers available on the shelf of your local garden center, or, in some cases you can even make your own. Here are some of the most popular types of natural liquid fertilizers.

Liquid kelp or seaweed
Fish emulsion
Fish hydroslate (or liquid fish)
Compost tea
Earthworm castings tea

The above products useful on their own, but they’re also quite valuable when combined with other ingredients. Natural liquid fertilizer combinations blend these products with ingredients such as liquid bone meal, blood meal, feather meal, and rock phosphate to create a well-rounded fertilizer and growth stimulant.

Liquid fertilizers for container gardens should be used once every few weeks.

Liquid kelp, seaweed, or fish-based fertilizers are an excellent choice for container-grown plants.

When using any natural liquid fertilizer, follow label instructions for mixing rates and application instructions. Generally, most liquid fertilizers are applied either by mixing the product in a watering can and watering by hand, or by using a hose-end fertilizer distribution system to automatically deliver the fertilizer with the irrigation water.

Applying liquid fertilizer to container gardening plants is easy with a hose-end sprayer.

Hose-end sprayers are a great way to deliver liquid fertilizers with irrigation water. Some brands, such as this one, come with the hose-end sprayer attached to a siphon bottle, but reusable hose-end sprayers are also available at most garden centers and hardware stores.

Liquid fertilizers are best absorbed when the plants growing in your containers are not under stress. Do not fertilize your plants when they’re wilting or suffering from heat stress. Water them first, a few hours before fertilizing them, to maximize their absorption of nutrients.

Though over-applying organic liquid fertilizers for container gardening is seldom possible in terms of plant health, overdoing it can be hard on the budget. Don’t use more than you need. Most liquid fertilizers should be applied every two to four weeks throughout the growing season.

To read more from Jessica about growing in containers, purchase a copy of Container Gardening Complete via Amazon, Jessica’s website, or your local bookseller.

The best, most complete container gardening book on the market.

Container Gardening Complete is a new book by horticulturist Jessica Walliser.

For more on tips on container gardening check out these posts:

Recipes for Making DIY Potting Soil
The Best Fertilizer Schedule for Houseplants
Container Garden Maintenance Tips
7 Best Herbs for Containers
Crops in Pots: Success with Vegetable Container Gardening


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109 Responses to Organic fertilizers for container gardening: The best choices for success

  1. George F Kovacs says:

    I love growing figs in containers. I am a resident of the U.S.

  2. Kim Bretz says:

    Love container gardening – this sounds like a great book!

  3. Deborah says:

    I have had off and on success with container grown vegetable. The book sounds great.

  4. Jessie says:

    We just moved two weeks ago and lost my raised bed garden, that I build from scratch, as a result. As I rebuild my garden in a new but temporary house, container gardening will become a big part of my garden plan. Indeterminate tomatoes, honey nut and summer squash, cukes, beans and peas, and strawberries are all things that I love to grow in containers. Despite my sadness over leaving my old garden behind, I can’t wait to find ways to grow in my new space! I live in Southern NJ outside Philadelphia in Zone 6b.

  5. T Tuokko says:

    Last year we did a variety of herbs, tomatoes and we tried ground cherries. All turned out great. I am from Canada

  6. Diane Corsi says:

    Container fun ahead!

  7. Jodi says:

    Herbs, herbs and more herbs.
    From Canada.

  8. Latrisha Dukes says:

    Us Resident. I have grown herbs, tomatoes and this year I did bell peppers which really did good and looked great. I’d like to try other vegetables like carrots and I e even seen lettuce grown in containers.

  9. Barb Hopkin says:

    I like to keep my peppers, both hot and sweet, in pots. I also like my basil in pots. It allows me to bring them in to finish them when the weather cools….still eating basil and hot peppers! Of course there’s are also the mandatory flute ownership pots that can be moved around the yard to offer color where needed.

  10. Cheryl McShane says:

    I like to grow my herbs in large and tall containers. It’s easy access to grab a few stems for a meal. No bending and untangling just snip and go back to your dish.

  11. Jane says:

    Containers for my tomatoes are the best. I can place them on the side of our driveway where I receive the best sun. Our lot is quite shady with 4 large silver maple trèes.
    Living in Canada is the best.

  12. Jane Reid says:

    I mostly do herbs due to available light, but this year added radicchio and some lettuces.
    I am in zone 5-6 in east coast Canada.

  13. Aileen Grant says:

    I don’t have a lot of ‘garden’ space, so containers are my best bet.I need more knowledge about this and the book would be just what I need! Proud to be Canadian!

  14. Dave Chapman says:

    I grow potatoes, zucchini, and cherry tomatoes in containers, and I’m trying garlic this year!

  15. Laura Robinson says:

    I love container gardening, especially my tiny Japanese Maples and my Meyer Lemon trees! My gophers and voles are bummed, but I have become a fan of container gardens after seeing my Gerber Daisies and other flowers turned into happy meals for local wildlife. I am in the US.

  16. Susan says:

    I just simply Love Container Gardening! I grow mostly flowers, Ivy, fillers etc. I especially love caring for them, watching them grow, flourish. It really makes me feel a sense of accomplishment and the reward… Beautiful Container Gardening.

    Thank you for the opportunity to enter to win this Wonderful Book. Cheers from Halifax, Nova Scotia Canada

  17. Sheryle G says:

    I love to grow peppers in containers. So much easier to take care of and they do much better than they did in my garden.

  18. Laura Horky says:

    I grow milkweed in containers for the Monarch caterpillers! In US

  19. Candace says:

    Mostly flowers since I’ve failed numerous times with veggies. I’m in the US.

  20. Janet Mackey says:

    I plant containers with flowers to attract hummingbirds and butterflies to our patio. I must admit that I’m not always good at keeping them well-fed all summer. I am in the U.S.

  21. nic says:

    love to grow tomatoes and herbs in containers. in Canada!

  22. Michele Schraa says:

    I love to grow herbs and hot peppers in containers.
    Please pick me for one of your lovely books.
    From Canada

  23. Dyan says:

    Much to our amazement we have been able to grow beautiful artichokes in containers during our Canadian summers. Jessica’s new book will certainly hone our growing.

  24. Dorrie C. says:

    I’m sure this book by Jessica is as good as the other 2 books she has written, as they were very informative on insects.
    I am a U.S. resident.

  25. Anne Mason says:

    In my container gardens I love to grow basil, tomatoes and cucamelons. Some years are good, more are not! This book sounds like a great resource! I’m from Canada:)

  26. Anne Mason says:

    In my containers I like to grow basil, tomatoes, and cucamelons. Some years are good, some not so much! This book sounds like a great resource. I’m from Canada:)

  27. Bryn says:

    I love growing in containers and grow bags. I love growing hot peppers in containers, as I have a season so it helps speed things along.

  28. Caroline says:

    Peppers! They always do better in pots in my Canadian garden.

  29. Janine Bennett says:

    I grow herbs in my containers. I am a U.S. resident

  30. Lisa Doucette says:

    I do 90% of my gardening in raised beds. But I love to plant flowers and cherry tomatoes in containers.

  31. Kala Mologne says:

    The book sounds like just I need! As I get older, it’s easier to use containers, plus herbs can be grown right outside my kitchen door. I hope it has information on tiny Japanese Maples and Meyer Lemon trees.

  32. Sam Crawford says:

    Oh my I would LOVE to win this book!!! If ny one needs it,it is me,lol….I do grow some herbs and tiny tomatoes, lettuce,..thank you for the opportunity to win!! I live in beautiful Nova Scotia,Canada

  33. Jeff Bowers says:

    I love to grow tomatoes and peppers in containers. I am Canadian.

  34. Rekha says:

    This Canadian resident loves growing tomatoes and peppers!

  35. Lloyd says:

    I love to grow Tiny Tim’s and Cherry tomatoes in containers! From Canada.

  36. Marie says:

    I enjoy creating planters out of objects other than pots. I like to mix herbs and annual flowers in antique cages and put them around my patio and porch. It’s fun to blend colors and textures. My cats also like to take refuge under the trailing vinca or asparagus fern. I live in the US.

  37. Curtis W says:

    All kinds of herbs, garlic and flowers for butterflies, bees and hummingbirds. Kansas USA.

  38. Marie Martin says:

    I like to grow Sweet 100 tomatoes & Herbs (Parsley) in containers.

  39. Marie Martin says:

    I like to grow Sweet 100 tomatoes & Herbs (Parsley) in containers.

  40. Derrell Hall says:

    Nasturtiums are my favourite; they produce lots of flowers and leaves that look like sand dollars; and I love to put the pepper-flavoured leaves and flowers on top of my salads for colour and flavour.

  41. Roxanne Lucchesi says:

    A resident of Pennsylvania, USA, I rent and cannot plant a fruit/veggie garden in the lawn. So I need to learn all about container gardening. Thus far I have only tried tomatoes and herbs — neither a smashing success. Obviously, I need a book like this to educate and guide me.

    Thank you for the offer.

  42. Pam says:

    I love growing tomatoes in containers on my deck, I am Canadan

  43. Linda sanderson says:

    Hi there,
    I garden in “growing” Kitchener, Ontario. Herbs are what drew me into container gardening, as well as houseplants, but we have been trying some veggies too to extend our beds. And now we have a few small nut trees (after visiting a tree farm) that we hope to plant in future on a country property.

  44. Kim Carter says:

    Northern Ontario, Canada! We are new to gardening and tried container gardener of Peas, Beans, Tomatoes, Broccoli and Green Peppers. This winter I hope to complete cold frames! (Somehow the deer got most of our in ground carrots and potatoes!)

  45. Janis Cann says:

    I enjoy growing herbs, flowers and tomatoes. I am from Canada.

  46. Eric H says:

    I grow cabbage, sweet potatoes, broccoli, peppers, lettuce, radishes, and more in containers! I’m in the U.S.

  47. Janet says:

    I love to grow tomatoes in containers. Here in Calgary we often get hail and cold nights. With my tomatoes in containers I can easily move them inside to keep them safe. I have often thought an interesting idea would be to combine vermicomposting with container gardening. Have you ever tried something like this? I am from Canada.

  48. Sue S. says:

    I enjoy growing flowers in containers here in Erie pa.

  49. Ariana Robbins says:

    I love succulent and cacti containers! I would really like to try peppers, tomatoes, and maybe guava in 2018. I would love to have this book for some guidance! I am a U.S. resident.

  50. Monica V says:

    I love growing tomatoes, annuals and perennial flowers in my containers.

    Great breakdown of fertilizers, was very helpful/informative!

    I am in Canada.

  51. Jenny Young says:

    My favorite things to grow in containers are annuals that explode in the fall. I also grow a lot of house plant inside & out.

  52. Bernice says:

    Well I used to do quite a bit of container gardening and stopped for a bit now that I use so many beds.

    I will need to use containers again next year to keep my carrots, beets and beans safer from critters having them for lunch.


  53. Cameron Milroy says:

    My Mom loves growing plants in containers!!! She is on the west coast of the US . Thank you for offering this to gardeners in the Canadian provinces also!
    Cheers !!!

  54. john says:

    We have mainly raised beds with hoop houses around our property because of poor soil quality (clay) and very successfully grow greens all year round. We plant
    cherry tomatoes in containers with great success and usually have a large urn of flowers and grasses on our front landing.

    Would love to add a copy of this book to our gardening library.

    John in Kitchener, ON Canada

  55. Dawn says:

    I grow an assortment of Salvias for the hummingbirds and a Sungold tomato for myself.
    US resident.

  56. Ellen S says:

    I grow herbs, tomatoes and most recently, peas in containers.

    I am from Canada.

  57. Elsa pihl says:

    I’m from Canada. In the past I’ve had a vegetable garden grown exclusively in containers. Tomatoes, cucumbers, herbs, Brussels sprouts, zucchini, carrots, beans, peas and more!! It wS fun because you have more control over the growing conditions.

  58. Lynn Dorcas says:

    I have a small green house and grow peppers,tomatoes,cucumbers,Swiss chard, kale,beans, and lots of herbs in it. As well, I use containers to extend my limited space garden out side.

    I live in Nova Scotia Canada

  59. Kathy C says:

    I’m looking to try vegetables. Tilling has gotten too hard. Congrats on the book Jessica!

  60. Susan says:

    Next season I will grow all of my tomatoes in containers to concentrate on more flowers in the beds. This book looks great!

  61. Suzanne Lamb says:

    December 6, 2017 at 9:37 am
    Container gardening is such a rewarding way to garden! I have been trying fabric containers lately, hoping to find plant combinations that I like, both for me and our bees!
    Nova Scotia, Canada

  62. Canadian, remote wilderness, Zone 3
    Thrust into the world of gardening and need a lot of help!
    Successfully growherbs, managed to keep strawberries alive, can grow tomatoes whose foliage feeds aphids!
    I live a gazillion miles from nearest grocery, have a tiny fridge, no freezer but luckily I’m vegetarian so I can eat grass…oh wait, none of that here either. So you see, I need to be able to grow my own food!

  63. Barbara L. Wallace says:

    I love container gardening because it allows me to grown sun loving plants in my few sunny spots on our very shaded forest property. Always have a wonderful havrvest especially my salad planters!!

  64. Sarah G says:

    I grow all of my veggies in containers. Lots of tomatoes!

  65. Beth H says:

    I’m new to container gardening – my new place has a tiny yard but a nice flat roof, so I’m looking forward to a rooftop container garden and how to make it work with tips from Jessica’s book! 🙂 US resident

  66. Rachel A says:

    Container bell peppers and tomatoes! Three pepper plants are still ripening their last peppers in a south-facing window after being moved inside the house (we’re in zone 5). I’m from Canada.

  67. Kripa Selvakumar says:

    I live in Canada, zone 6. I have successfully grown variety of vegetables like tomatoes,okra,peppers,egg plants, potatoes,etc., and flowers and herbs in various containers in my small balcony garden in a high rise condo. After moving to a new house, I started using ground, raised bed as well as containers. But still I feel the yield in containers are more when compared to the ground. Especially the potato yield was high and in good quality in containers. Its easy for moving around the garden too. Variety of containers add to the beauty of landscape. I love container gardening and looking to gain more knowledge about it.

  68. Isabelle says:

    Absolutely love growing tomatoes in containers, but recently discovered the joys of growing potatoes as well! Love how containers provide us to grow more during our short season here in Calgary. 🙂

  69. Rose says:

    This year I planted several layers of bulbs in a big container – tulips mostly and some hyacinths. They are an experiment in timing – there are early, middle and late varieties. Really looking forward to seeing how they all come up next Spring. And in the middle of the container is a miniature rose to anchor the display. Once the bulbs are over I hope to pop in some annuals for the summer and autumn.

  70. Jer says:

    Another great book full of useful knowledge for Gardeners everywhere

  71. Galanda says:

    I love in the US and I love to grow herbs in containers.

  72. Rose Weber says:

    I mostly grow annuals in containers, but plan to experiment with vegies next year. Loved the info about fertilizing.

  73. Sharon Schwartz says:

    I grow elephant ears & Brugmansias in containers, plus cukes, peppers, some tomatoes, & many different basils, & flowers. I would love this book! My favorite organic fertilizer is “poop soup” from my dads organic grassfed cattle.

  74. Carolyn says:

    I live in USA and like to plant tomatoes and annual flowers in containers.

  75. Julie Metivier says:

    I love growing herbs in containers. I live in NS, Canada

  76. peter prosser says:

    I grow giant pumpkins and this fall I made a giant container of sorts to grow my pumpkin in , a three foot high , 8×8 foot box , no bottom which will have its own irrigation and a heat source for the spring. In Canada, (N.B.)

  77. Laura newkirk says:

    I like to plant several silvery grey dusty miller plants in my full sun containers along with purple and white flowers. At summer’s end I pull the coloured annuals and replace with flowering cabbage or kale. These along with the dusty millers keep going strong until hard frost. From Canada.

  78. Laurel Hounslow says:

    I would be so excited to win this book. Our clay soil and short Zone 3 season make it hard to get good production so have been trying to switch over to a variety of containers. My grandchildren are very involved from planting to watering to harvesting in raised beds and various pots. Guidance of the kind Jessica provides would be so very welcome in helping me grow a new generation of gardeners. Thanks for the opportunity and happy gardening to whoever wins.

  79. Gina Bianchi says:

    I love growing herbs in containers! I am from the US!

  80. Ruth says:

    Love growing lavender and mint! Live in Zone 5 (Seattle area (U.S.A.) and will be trying some new herbs next summer. Congrats on the new book!

  81. Jay Goforth says:

    US resident. I love to grow potatoes, herbs, and flowers in containers.

  82. Philip Grombliniak says:

    My granddaughter and I love growing tomatoes. We enter many of the gardening showcases here on Long Island New York USA. We love to try growing different varieties every year.

  83. Heather says:

    My name is Heather, I’m a U. S resident and am growing squash, green onions and basil in containers! Thanks for the opportunity! Cheers!

  84. Barbara Sanders says:

    I grow all kinds of different plants in containers. I fill two half barrels on our deck and several other smaller pots with plants. I always plant my geraniums in containers so I can overwinter them by just taking them inside to our Cool cellar. I love Savvy Gardening website; you always have such great articles. Thank you. I’m in the U.S.

  85. Dale Odorizzi says:

    Canadian Resident I just moved from a large rural property with a huge vegetable garden to a condo with a large terrace. I have always grown flowers and herbs in my containers in the past but hope to grow lots of vegetables, especially tomatoes. We moved here mid summer and I did grow one tomato plant and one pepper plant but plan much much more. Looking for all the help I can get. Thank you

  86. Suze says:

    I love growing peppers in containers. Now that the weather is too cold, ive pulled my habaneros, cayenne, and rezha inside. I hope to overwinter them so I get a head start on spring 2018!

  87. Bob Crowhurst says:

    I tried tomatoes and peppers in a grow had this year. Canada.

  88. Adena says:

    I have a tiny balcony in Nova Scotia, Canada and I love to fill it with plants every year. This year I’m trying to overwinter my perennial containers outside on my balcony. Fingers crossed!

  89. Rita says:

    From BC Canada, I enjoy container growing herbs, flowers, peppers, etc. I have a big fig tree in a sack container that was drug into the garage for the winter. This will be its sixth year. Can’t get much bigger!

  90. Jim Charlier says:

    Hostas. I’ve got more than a dozen in pots I overwinter. From small to ginormous. US.

  91. Shawna says:

    I love planting my herbs in containers. Here in Canada, I can bring them inside when the weather gets bad!

  92. AnnaMarie Lohr says:

    I have a fig tree growing year 4 in a container and grow annuals in containers in the summer. I’m a US resident.

  93. Ron Mitchell says:

    Some flowers, herbs and veggies are just better in containers. This year I planted 2 orange flowering lantanas in a large blue container. Not only did it look spectacular but it attracted a few species of swallowtails such as Eastern Black, Tiger and Giant. Sweet peppers are almost always eaten up by insects or rabbits. In a container they seem to be left alone and grow so healthy. As for herbs, basil seems to put on vigouours growth, giving me lots of leaves to dry for winter use in my tomato dishes. Long live the container!
    From Canada.

  94. Nancy says:

    tomatoes, and flowers
    US resident

  95. Jeff Johnson says:

    Tomatoes in containers

  96. Lynette says:

    Hello!!!! I just completed my master gardening class thru msu in Michigan. I would love to add your book to my collection.

  97. Christine Meissner says:

    I grow bougainvillea in large containers. Lots of beautiful flowers.
    Live in the USA.

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