Module 3: Choosing Plants & Seeds
When & What to plant.
Note: This module is packed with information. But not to worry, it's not all for things you need to do right away. Because this module deals with choosing seeds, this module has everything you need now for your first round of spring planting, and to plan ahead for summer and fall.
The tables specifying what to plant are organized by approximate region & serve as beginner reference guides However, the world of edible plants is vast and extends far beyond what we’re presenting here. Our goal is to guide you throughout the entire growing season with plants that will generally thrive the most.
Introduction
So now that you're working on your space and soil, naturally your mind is probably thinking about what you can or ought to plant. There's just one thing missing: seeds.
Problem is, many seed catalogs have such an astounding array of options, it's very difficult to make the best choices for your climate, location, and garden size.
Even a simple search like "peppers" unleashes a bewildering array of Latin words, exotic choices and seductive descriptions.
Russian or red kale? What about the normal green stuff? Genovese or Thai basil? Japanese daikon? Purple carrots? What the heck is kohlrabi?
And that is how you make your first big gardening whopper. Just like every other mistake that happens when you are overwhelmed with too many choices in unfamiliar terrain.
Like any other skill, gardening comes with its own vocabulary. You will learn more as you go, but for now let's clarify just enough terminology to help you decipher the seed catalog and those little packets.
Annuals & Perennials
Annuals are plants you need to plant again from seed every year. Perennials are plants that regenerate on their own each springtime. There are also biennials which will come back for a second year, and often only produce fruit in the second year. And also there are tender perennials that will regenerate every year as long as the winter is not too harsh. For example, sage is a tender perennial. It usually regenerates after a mild Mid-Atlantic winter, but not after an arctic Chicago one.
A good garden will always have some perennials, and a sustainable, ecological garden will have many. Why plant the whole garden year after year when there's wonderful options that will regenerate on their own?
A garden that demands constant attention — and financial investment! — from the gardener can very easily feel like a time-consuming chore and very expensive hobby. In a world beset by pandemic and increasing social unrest, we don't have time to fuss over every leaf of lettuce. What happens to the high-maintenance garden when we go back to our busy lives?
Fortunately, there’s the wonderful world of perennial plants to help us grow food and have a life too. SEEK THEM OUT. With a good support structure in place, the gardener can tend to the garden as a part of life in balance with everything else.
Benefits of Perennials
Perennials cultivate soil
fend off weeds
attract pollinators and pest-controlling predators
provide an astonishing variety of food, herbs, medicine, and beautiful shapes and colors.
Seed Spacing: Does it really matter?
Along with telling you whether the plant is an annual or perennial, seed packets will also usually give you a recommended amount of space when you plant the seeds. For example, they will tell you to plant lettuce seeds 4-6 inches apart but eggplant or beans one foot apart — or something like that.
Why? What’s the big deal? Do you really need to be out there measuring exactly how much space you give each and every seed?
Well, yes and no. But mostly no. Here’s why:
Different plants grow to different sizes. So of course it makes sense that larger plants need more space. Fine, let’s give them their space.
However, plants also have different nutrient requirements and that depends more on their type than their size. Plants producing mostly green leafy foliage need more nitrogen, for example, while fruiting plants need more potassium. So sure, if you plant all leafy plants (like kale) in one spot and all the fruiting plants (like tomatoes and eggplant) all together in another spot, you’ve created a scarcity — and therefore a competition.
Can’t we all just get along? Yes, but in order to encourage cooperation, we need to cultivate diversity. If you plant different plants with different needs together (instead of one type), plants can more easily share the nutrients in the soil amongst each other.
The key is to interplant a variety of plants strategically. Let's see how this works.
How-To Instructions
3.1 Interplant Varieties
Let me give you a concrete example of how interplanting works.
Cauliflower is a notoriously hungry garden vegetable, needing a lot of nutrients to form those lovely yet massive heads. So the spacing recommendations for cauliflower on a seed packet will be generous. Does that mean you have to leave big empty spaces in between your cauliflower plants, open to marauding weeds to colonize?
Instead of leaving big gaps around hungry plants, why not fill those spaces with less demanding, faster-maturing tasty edibles like arugula and radishes? By interplanting different kinds of plants with different root sizes together, you can minimize competition for resources and you get more varieties of food.
What types of vegetables should you interplant? Well, experimentation is the key to success, but here’s two good general rules of thumb:
Age matters.
Plants of different maturing times go well together. Arugula and tender salad greens are ready for harvest quickly, within 4-5 weeks. So you can plant them at will in between slower-maturing plants like eggplant or cauliflower. By the time the slow grower is setting fruit, the greens will be in your salad.
Go by looks.
Leafy plants interplant well with fruiting plants since they usually have different nutrient needs. You can even combine based on cuisine! Some good combinations are basil with tomatoes for Italian dishes or mustard greens and eggplant for Indian fare.
Look at the roots.
Plants of different root types will pull nutrients from different parts of the soil. You can minimize competition (and pack more plants into a smaller space) by diversifying your plant selection based on what the root looks like. Carrots, onions, and cabbage/lettuce are a trio that work well together, for example.
3.2 How to Understand Plant Hardiness Zones
You’ll notice the seed packets usually reference the Hardiness Zone for that particular plant. What is that?
Plant hardiness is basically a measure of “how low can a plant go” in terms of living with the outdoor temperature. Plant hardiness zones range from 1-10, with 1 being the coldest and 10 the hottest.
The vast majority of garden variety herbs and vegetables survive and thrive in Zones 3 through 8. However, that’s a very wide range. Plant zone hardiness is only a very basic guideline and really not the best way to determine what will really do well in your garden. Search online to find your zone.
To choose plants wisely, you would do much better to think about adjectives that describe your climate. “Wet and cool,” for example, or “long cold winter” and “muggy hot summer.” Those descriptions will serve you better.
Therefore, we’ve organized the What to Plant When guides (at the end of the module) accordingly, using climate descriptors rather than Hardiness Zone numbers.
Why? Well, let’s look at a common garden plant like tomatoes. The tomato plant will survive anywhere from Zones 3 thru 9, but you grow tomatoes for the fruit, not the plant. Large heirloom varieties of tomato are likely to get soft and wormy in very hot muggy conditions, or mildewed in cool wet weather. If you live in such a climate, you can still grow tomatoes but choose a faster-maturing variety like cherry or Roma (plum). Salad greens that flourish in cool weather will bolt and become bitter in the heat, and so forth.
When it comes to cultivating plants, climate is really everything.
You can adjust for many climate factors by choosing not just the right plants, but the right varieties that will thrive in the specific conditions of your climate. I’ve created these guides to help you streamline your selection process, but don’t be afraid to experiment. Experience is the best teacher.
3.3 Seeds or Starters*?
*A starter is a baby plant started for you, usually in a nursery greenhouse
The vast majority of garden vegetables and herbs can and should be started from seed right in your garden.
Particularly if your location and climate graces you with a long growing season (Zones 5 - 9), you can potentially grow everything your heart desires from seeds planted directly in the garden. Fast-maturing plants like radishes, most leafy greens, parsley and pearl onions, are fine planted in the garden (without transplanting) even in the far north. The same goes for cold-hardy veggies like parsnips, rutabagas, and kale.
In areas with frosts that persist into May and hit before Halloween, you can germinate seeds for crops that take a long time to mature (70+ days) in containers and plant them in the garden on or after the "setting out" date, or 2 full weeks after the average last frost date.
In either case, whether you are planting seeds directly in the garden OR transplanting starters, wait for 2 full weeks after the average last frost date.
Seriously folks. Wait for it. Too many tender little seedlings have perished in freakish late cold snaps because people let their eagerness get the better of them. Cultivating a garden is as much about patience as it is about plants.
What about those cute baby plants all the garden supply stores are selling right now? Even Whole Foods has a whole display outside...can I get some of those?
For a hard-core DIY-er, my answer may surprise you: yes, absolutely. If you didn't start seedlings early--and I'm not saying you should have — buying starters is perfectly ok. I would only ask that you support a small local garden center or farmers market instead of, you know, Mr. Bezos. He doesn't need your $10 for a tray of pepper plants, nor does he care if you grow them at all.
In addition, while most seeds are hardy survivors, some of our favorite veggies are notoriously fickle. They need warm air, warm soil, just the right moisture, etc. It's just easier to buy them started for you in a greenhouse, and that's ok, especially if you are new to growing food. After your rookie season, I encourage you to experiment with more direct seeding.
Then there are plants that really dislike being transplanted. Being uprooted is stressful for all plants, but some have a harder time recovering—if they do at all.
To help you choose between starting from seed or investing in starters, simply consult this guide:
PLANT SEED DIRECTLY IN THE GROUND (two weeks after avg last frost)
All leafy greens
Small tomato varieties (e.g. cherry, grape, roma)
All brassicas and chicories (e.g. cabbage, endive, radicchio)
All root crops (e.g. radish, potato, carrot, beet)
All legumes (beans and peas)
All melons and gourds
All squash
Annual herbs (e.g. basil, parsley, cilantro)
Annual flowers (e.g. sunflowers, alyssum, nasturtium, marigolds)
Perennial greens* (e.g. sorrel, purslane, lambs quarters)
*Starters for perennial greens are hard to find, but seeds are generally available. They will grow slowly the first year, but are worth the wait. Be patient. Next season, they'll be back bigger and stronger.
USE STARTERS AND TRANSPLANT
Eggplant
Large heirloom tomatoes
Sweet/bell peppers
Perennial herbs* (e.g. oregano, sage, thyme, rosemary, chives)
Perennial flowers* (e.g. coreopsis, bee balm, yarrow, lavender)
*I recommend buying a few starters because perennial herbs and flowers grow very slowly in their first season. Invest in a few from your local nursery or farmers market so you (and the bees and butterflies) can enjoy them this year. But you can also start your own from seed in pots in spring. Let them grow and get stronger throughout the summer and transplant in early fall 3-4 weeks before the first frost)
3.4 Best Plants for a Small Space
When you're working within a smaller space, strategy is important to getting the most out of it. By choosing plants with faster maturing times that take up less space, you can still harvest and enjoy fresh produce all season long.
Here's a guide to your best options:
Tender leafy greens: can be harvested young to encourage more production, good for dense planting
Grape tomato: prolific producer faster maturing, needs less space
Pickle cucumber: faster maturing, can grow vertically
Delicata or other small variety squash: prolific, can grow vertically
Pole beans and peas: prolific, can grow vertically
Chard: Heat tolerant, good for dense planting, produces continuously
Carrots and Parsnips: grow straight down (need less space than other roots
Yukon Gold/small potato variety: prolific, can grow in a box, barrel, or container
3.5 When to plant What (by region)
These plants tables are to be used as general guides; they are non-exhaustive lists of the plants that will thrive in general approximated regions. Different varieties of the same plant may thrive in different climates and it’s important to do your research when sourcing seeds. Do not fret if we do not have a certain plant listed in your region, as there may be varieties that will thrive in your climate - research to see what you can find.
Remember to consider the weather & climate patterns of where you live rather than relying on USDA hardiness zones. Do your best to find an independent seed producer local to your region. Most of the plants listed can be grown in a relatively small space if you practice succession planting, which will be covered in Module 4.
Remember:
Tender greens will bolt and turn bitter in hot weather, they are best planted early and late in the season.
Avoid harvesting perennial vegetables in the first year to allow healthy and thorough plant establishment. Asparagus can be harvested starting in the 3rd year.
Perennial herbs often are slow-growing. Nursery starters can be advantageous over seeds.
Perennial fruits grow in a wide variety of fashions - research your favorites and find sources local to you. Many are even available by mail.
Many fall crops can be overwintered and enjoyed into the Spring of the next year.
Resources
Biodegradable seed starting cups: https://parkseed.com/square-jiffy-pots/p/v1593/
Seed Sources
https://www.westriverseeds.com/
https://www.southernexposure.com/
https://www.earthbeatseeds.com/