1. All New Square Foot Gardening by Mel Bartholomew
​This is a classic gardening book. Although I give some plants more room than he suggests this is a great resource on dense planting and getting more harvest out of a small space.

2. Epic Tomatoes: How to Select & Grow the Best Varieties of All Time by Craig LeHoullier
Tomatoes are one of my favorite plants to grow in my garden so this is one of my favorite gardening books. Epic Tomatoes is a great resource from a tomato expert and on how to grow tomatoes, save seeds, and even breed your own varieties. I also love the list at the end of the book on his favorite 250 varieties. I have yet to even grow 250 varieties, much less have 250 favorites! My only caveat in this book is to not follow his method of canning tomatoes. He claims he still follows the basics of the Ball Blue Book but then states he does not bother to remove the tomato skins. Unless otherwise specified (a very, very few canning recipes allow the skins to remain) all tomatoes must have their skins removed before canning. The skins can harbor high levels of bacteria which can potentially cause your canned goods to go bad or even make you sick. If you do not want the hassle of removing skins, simply freeze your product instead of canning it. See my previous post on safe canning if you wish to learn more.

3. Garden Insects of North America by Whitney Cranshaw and David Shetlar
I use this book as a reference guide when I wish to identify an insect or learn more about a specific one. This book contains almost 700 pages of pictures and information on the majority of insects that can affect gardens in North America. I used this book to help me identify a thrips problem in my hydroponic grow system

4. Growing Great Garlic: The Definitive Guide for Organic Gardeners and Small Farmers by Ron L. Engeland
This is one of those books that I feel like I have had forever, at least since I was a teenager (I was a gardening nerd even then). The title says it all, if you want to grow great garlic, read this book. This is a comprehensive guide to growing garlic that will help you determine which varieties to grow, how and when to plant, what to use for fertilizer, and more.

5. How to Grow Vegetables Organically by Jeff Cox & the Editors of Rodale’s Organic Gardening Magazine
I use this as a reference guide when I need to look up specific growing requirements, fertilizers, soil types, watering guides, and more for certain vegetables. Although this is an older book and I wouldn’t mind updating to a newer organic grower’s guide, this book is still full of valuable information on basic gardening. A great all-purpose guide to gardening.

6. Saving Seeds: The Gardener’s Guide to Growing and Storing Vegetable and Flower Seeds by Marc Rogers
This is a great starting guide if you are interested in saving seeds. It covers everything from easy plants like tomatoes and peppers to difficult-to-save seeds due to cross-pollination like squashes and pumpkins. It also covers cleaning, storing, and testing the germination of the seeds you save.

7. The Winter Harvest Handbook: Year-Round Vegetable Production Using Deep-Organic Techniques and Unheated Greenhouses by Eliot Coleman
Although this book is still in my to-be-read pile (I hope to get to it this year), Eliot Coleman is well known for his Winter Harvest Handbook and Four-Season Harvest books which explain how to extend your gardening season.

8. Vegetable Literacy: Cooking and Gardening with Twelve Families from the Edible Plant Kingdom, with over 300 Deliciously Simple Recipes by Deborah Madison
This is more a cookbook than a growing guide but still full of valuable information. Vegetable literacy is a large volume containing descriptions of the different edible plant families with beautiful pictures and tasty recipes. If you want to learn more about the plant families you are growing in your garden, this is the book for you. 

​I see a lot of confusion online about the different types of seeds that are available for purchase. Here I will attempt to clarify the differences between them, allowing you to make the best-informed decision about what types of seeds are best for your garden.

​Open-pollinated and heirloom seeds are similar in that both types of seeds can be saved year after year as long as they are grown distanced from different varieties of the same species to prevent cross-pollination (1). These seeds are genetically stable and manifest similar phenotypes (physical characteristics) when grown (1). Open-pollinated seeds arise from cross-pollination of separate plants of the same species AND variety or self-pollination from the same flower or separate flowers on the same plant (1). Self-pollinating varieties can generally be grown closer together with less risk of cross-pollination but unless you isolate the flower and hand-pollinate there is always the risk that the wind or an insect cross-pollinated for you if another variety of the same species is growing nearby (1). Tomatoes and peppers are probably the most saved seed by home gardeners, and I found that peppers are more likely to cross than tomatoes. I do not attempt to isolate my plants because I am only saving seeds for my use, and I do not mind the uncertainty of growing a possible hybrid the following year.

​Heirloom seeds are an older variety of open-pollinated seeds (1). Generally, any seed older than 50 years is considered an heirloom but that is not universally agreed upon (2). Heirloom seeds must be open-pollinated but open-pollinated seeds are not necessarily heirlooms. If you are interested in saving seeds and want to make sure the seeds you collect will grow to be the same as their parents, then you must use open-pollinated or heirloom seeds. New varieties of open-pollinated plants can be made using labor-intensive traditional plant breeding methods that involve crossing 2 varieties, collecting the seeds from plants manifesting the characteristics you are looking for, growing new plants from those seeds, and repeating for many years until you have a stable seed that produces the same type of plant year after year. Although new open-pollinated plants can take years to develop, once you have stable seeds, they can be propagated easily via saving seeds (assuming no other varieties were nearby to cross-pollinate).

​Hybrid seeds (also known as F1, or first generation after the cross seeds) are from cross-pollination of two genetically different varieties of the same species of parent plants (1). The usual way to create these can take years and lots of testing to determine that the phenotypes you want (characteristics such as color, disease resistance, size, etc.) are present and stable in the offspring. Because of the time it takes to generate new varieties of hybrid plants and because to make seed a grower needs to perform this cross-pollination each year (1), which is labor-intensive, is why hybrid seeds cost so much more than open-pollinated or heirloom seeds. Hybrid vigor is a phenomenon that often arises when two different plants are crossed and is one of the reasons why hybrids are so popular (1). You can save seeds from hybrid plants but there is no guarantee that the plant that grows from the saved seed will be the same as the parent. I have successfully re-grown some hybrids (but not most) from seeds that looked just like the parents so if you are willing to experiment there is no reason you cannot save hybrids. If you are not interested in experimentation, simply stick to saving open-pollinated or heirloom seeds. Importantly, hybrid seeds are NOT GMO (genetically modified organism) seeds.

​GMO seeds are developed by genetically engineering the genes from one species into another (2). This is done for a variety of reasons such as disease resistance, pesticide resistance, or increasing a desirable trait such as more nutrition. Most gardeners appear to be vehemently opposed to GMO seeds, but they may not be aware that 70% of the processed foods in the United States come from GMO ingredients (2). However, although you may be unwittingly eating GMO crops, GMO seeds are generally NOT available to the average home gardener (see update below!), they are primarily used by commercial farmers to grow corn, soybeans, canola, sugar beets, and cotton (FDA). Other non-processed foods that may be GMO in the United States include certain varieties of potatoes, apples, summer squash, papaya, and pink pineapples (FDA). Many people want to avoid every GMO crop which although extremely difficult is certainly an option. I think GMO crops and seeds need to be taken case by case. As an example, the Hawaiian papaya would likely have gone extinct due to a ringspot virus but was saved by genetically engineering a resistance gene into the plant. On the other hand, the practice of engineering pesticide-resistance genes into our commercial crops so that we can spray more herbicides on our crops without killing the crop itself is not a practice I am in favor of.

UPDATE on 02/07/24: As of February 2024, the first bioengineered seeds are available to home gardeners from the Norfolk Healthy Produce company. They inserted a purple color gene from an edible snapdragon plant into a tomato genome. This makes a very purple tomato with increased anthrocyanin, an antioxidant that gives purple vegetables their color. This tomato has been vigoroursly tested and is deemed safe by both the USDA and FDA. Because these seeds are under patent the fruit, seeds, or plants cannot be sold by anyone other than the company that developed them, they are also very expensive! If you want a very purple tomato that is non-GMO Baker Creek Heirloom Seeds is trying to bring the Purple Galaxy Tomato to market. They were supposed to be available early this year but due to production issues will no longer be available to purchase (they even featured it on the cover of their 2024 seed catalog, oops!) Hopefully seeds will be available soon! In the meantime, there are lots of other heirloom and open-pollinated purple and black tomato varieties available, try them all!

​I grow mostly open-pollinated and heirloom seeds (especially my tomatoes and peppers), but I will occasionally grow hybrids usually for specific reasons such as disease resistance, reduced bolting, or easier growth. I lost all my cucumber crop one year to downy mildew so ever since then I have grown at least one type of downy mildew-resistant cucumber variety along with my open-pollinated varieties. It is also possible that you can find open-pollinated disease-resistant varieties if you do not wish to grow any hybrids however in many cases disease resistance may not be as well documented, so it may take some trial and error with different varieties to find one that works. The other type of crop I generally grow from hybrid seed is broccoli and cauliflower. We tend to have large temperature fluctuations in the spring, and I grow much more consistent heads of broccoli and cauliflower with hybrid seeds than open-pollinated ones.
One last note on the “organic” seed label. Organic simply means a seed was grown under organic conditions as defined by the USDA’s National Organic Program (1) This means that any fertilizer, pesticides, or any other treatment used to grow the plants must all be labeled organic, and the seeds cannot contain any genetically modified genes. There is no difference genetically between a seed of the same species and variety that was grown organically versus one that was not. You can purchase organic hybrid seeds just like you can purchase non-organic heirloom seeds.