Culinary Herbs - Growing, Harvesting and Preserving
Updated: Apr 27, 2022
It's herb month! This is the first in a series of four articles on culinary herbs. Today, we will go over the basics of growing, harvesting, propagating, and preserving these guys. We will follow this up with three articles that go into more detail on each individual herb, one for annual herbs, one for tender perennials and one for hardy perennials. See below for the links to these. There are a ton of options when it comes to growing herbs in our climate. Seriously, wait until you see how many we can actually grow!
In general, herbs are just plants that are valued for their flavour, aroma, or medicinal properties. We are going to concentrate on culinary herbs only. Medicinal herbs include many, many more species and can be tricky to recommend safely, so we are going to stick with the ones we can safely eat. Food is my forte after all! And we are also going to focus on herbs that can be successfully grown here in our climate, with at least some of its time outdoors. Sorry, no black pepper or ginger.
So why should you grow herbs? One simple reason: flavour! The leaves, stems, flowers, seeds, and roots of these plants can add infinite zest and zing to all your foods: soups, stews, salads, vegetables, meats, breakfasts, and baking too. They can be eaten fresh, right out of your garden, as either small nuances or as large components of a dish. They can also be frozen or dried to keep that flavour train going all year round. Herbs can bring us warm comfort in a steeped tea and they can transport us to far-off lands to experience another culture through food. The strong aroma and taste of herbs can invoke powerful memories and feelings in people. Never underestimate the power of great-tasting food to inspire, comfort, and create emotion in people! Herbs are the ultimate in yumminess.
How To Get Herb Plants
You can grow herbs by either starting them from seed yourself or by purchasing already started plants (also called transplants) and growing them further in your own garden. There are pros and cons to both methods.
Buying starter plants
This is a great option if you are just starting
out with gardening or have limited time. Transplants can be very simply popped into a container or bed outdoors once the temperatures are adequate. Easy peasy! You can start harvesting fairly soon after planting; no waiting for seeds to germinate or plants to get to a mature size. This can be a huge time saver! While some herbs will germinate and grow fairly quickly (as short as 40 days to harvest for some parsley or cilantro), a large number of herbs can take many months to get to a harvestable size, and some tree or shrub herbs can take years. There are some drawbacks to this option though. Starter plants can be expensive, especially if you are going to be buying a number of them. While seeds can cost pennies each, transplants run in the dollars per plant. The other drawback, and this is a really big one for me, is the lack of selection. When buying starter plants, you are at the mercy of whatever herbs and varieties your garden center happens to have at the moment. That may a fair number of herbs during those 3 weeks at the beginning of the growing season, but it can be next to nothing for the rest of the year. And finding a specific variety of an herb can be next to impossible if it is not the most common one.
When purchasing herb transplants, look for:
healthy foliage with no blotches, or physical damage
compact plants that have multiple branches and lots of leaves
healthy roots that are not pot bound (wrapping around the inside of the pot)
no signs of insect damage or disease
bigger isn't always better (smaller plants will catch up quickly), healthy is better
Starting from seed
This is a better option if you like to grow different varieties of herbs or if you like the control of knowing exactly how your plants were raised. You know for sure that no pesticides were used if you grow them from seed yourself! As mentioned above, it is also a far cheaper option. A little bit of planning does need to happen with seed starting to ensure plants will be ready to harvest by the end of the growing season. Many perennial herbs will need to be started in February or March indoors in our climate. In terms of process, starting herbs is just like starting any other plant from seed. You can refer to the article All About Seed Starting for step-by-step instructions. When plants can go outside will be determined by the type of herbs they are: cool season herbs or warm season herbs. Some can hack our cooler spring temperatures and some prefer warm Mediterranean type weather. Check out the next two herb articles for specific seed starting, transplanting, and direct seeding times for each individual herb or go to Part 2 in our series on Crop Planning for detailed instructions on working out your seeding and transplanting dates for your entire vegetable garden. And don't forget to check your seed package too.
It doesn't matter if you are starting seeds from scratch or buying transplants from a garden centre, all plants will need to be hardened off before being exposed full time to the great outdoors. Full-on cool nights, wind, and insects can be a big shock to plants that have been coddled indoors their whole lives. See Transitioning Transplants to the Garden for a how-to.
There is another option that many people forget about for herbs, and that is growing them as sprouts or microgreens. This is a fantastic way to get super healthy herbs in your belly super quickly. Sprouts can be ready to eat in as little as 3 days, while microgreens can be harvested in 7 to 14 days. Fast, right? Many of our herbaceous herbs can be easily grown this way and add huge pops of flavour to any dish. Try basil, fenugreek, mizuna, or cress as sprouts. For microgreens and shoots try nasturtium, chives, parsley, basil, cilantro, dill, chervil, and lovage. Refer to the article Sprouts, Shoots and Microgreens for more instructions and great ways to use them.
I know we have covered this quite a few times, but it always helps to repeat it just once more: healthy soil equals healthy plants. This is equally true for herbs. Soil that has lots of organic matter, is not compacted and is full of soil organisms that will grow tastier and healthier herbs. However, not all these plants share the same needs when it comes to sun, heat, moisture, and soil drainage. The array of herbs that we grow in our gardens originate from all over the globe, from the Mediterranean to the mountainous regions of northern Asia. We can guess what environments each prefers by studying where they are indigenous to, or we can just look at the plant tag! This is why a single herb bed in our gardens is not always the best idea. We need to create too many microclimates to jam them all in one spot. So look for the most ideal spot in your growing space for each individual herb to ensure it has the very best environment for it to grow. Check out the next two articles on herbs for specific needs for each (links can be found below).
Most herbs are also ideal candidates for container gardening. The portability of containers allows you to move them around throughout the growing season to adjust for light, heat, wind, and moisture exposure. It also makes them super easy to bring indoors for the winter months. Perfect for overwintering perennial herbs that are not hardy in our climate! Pots are also pretty much mandatory for extra spready herbs like mint that will take over your garden if planted in the ground. Keep in mind that you will need to water pots more often as they dry out far more quickly. You will also need to amend the soil in containers more often as they do not have the same amount of soil and nutrients to draw from as those in the ground. Don't forget to consider the size and weight of your pots (especially when filled with soil, water, and plants) when choosing them, particularly if you will need to move them later.
Fortunately, most herbs are pretty close to pest free. This is most often due to their strong smell and flavours, the things we are typically growing them for. In fact, many herbs are fantastic companion plants for this very reason. They deter many pests from other plants nearby with their odor. See the article on Companion Planting for the Veggie Garden for specifics and planting strategies. If you do happen to see something munching on your herbs, take a moment and identify exactly what it is. There are many butterfly species whose larvae (caterpillars) depend solely on some of our culinary herbs for food. One example is the black swallowtail butterfly whose green and black striped larvae just loves dill. By the way, that goes for any pests you find in your garden. Always identify before you squish or spray. There are lots of good guys out there! A good strategy is to plant enough to share.
The parts of the plant we use as herbs can be the leaves, stems, flowers, fruit, seeds, or roots and many herb plants have more than one part that can be used (hello cilantro!). How we harvest them will depend on which parts we are going to use.
Collecting leaves and flowers
Individual leaves or flowers can be continually harvested throughout the garden season by pinching or clipping them. Pinching back is the process of removing the entire growing tip (including one to three sets of leaves) to encourage multiple branch growth and increased bushiness in a plant. It is a form of pruning where you get to eat your cuttings. You can also remove entire stems if you need a larger amount all at one time. Just ensure you do not cut off more than around 1/3 of the plant at a time to be sure you have continued healthy growth. Leaves and stems should be harvested before flowering to ensure the best and strongest flavour. Flowers are best harvested in either bud stage or just coming into full bloom. No drooping or falling petals.
Seeds should be harvested when fully mature but this can be tricky, as many plants like to drop or even fling their seeds away the second they become ripe. The easiest way to collect them is as follows:
place a paper bag over a group of flowers (or over a group of seed pods)
gather the stems into a loose bunch and tie them together with a string
cut off the bunch with pruners or sharp scissors
hang the bunch upside down in a cool, dry area (like you would to dry fresh herbs, see photo below)
this way, the seeds fall into the bag as they completely ripen
Place your bags just as the seed pods are beginning to ripen (when they start to turn brown) or once you see seeds begin to form on umbral type flowers. If you like, you can also collect seeds right in the garden by placing your paper bag and then bending over the stem so the seeds fall downward into the bag. You will need to ensure that you have dry weather to allow this to work.
Collecting roots and rhizomes
Most bulbs, rhizomes, and roots should be harvested later in the season when the leaves have partially or fully died down. For biennials, underground portions should be collected in either their first fall or second spring to get them at their most tender and least woody. Check out the article Garlic - The Stinking Rose for all the details on growing, harvesting, and storing our most popular bulb type herb.
End of season harvest
There are a number of herbs that are hardy perennials in our climate. These herbs just need to be left alone and they will sprout each spring and produce year after year.
Hardy perennial herbs include: chives, beebalm, catnip, echinacea, anise hyssop, english lavendar, lemon balm, lovage, some mints, rose, winter savory, sorrel, sweet cicely, sweet violet, thyme
Garlic, some onions, and horseradish, although technically perennial, are usually dug up in late summer or fall to be harvested and smaller portions of the roots or bulbs replanted that same fall.
The majority of culinary herbs are either annual plants or are tender perennials in our cold location. We can treat these in two different ways at the end of the growing season. We can either remove all of the edible parts (leaves, stems, flowers, seeds, etc) and store or preserve them in some way (see below), or we can dig them up, roots, soil and all, and put them in a pot to grow them as indoor plants over the winter. Growing these herbs in containers outdoors all summer, makes this transition to indoors particularly easy. You just need to move the pot! If your chosen herb happens to be a particularly large specimen or one with a tap root, then taking a softwood or semi-ripe cutting to propagate the plant might be a better alternative (see the section on propagation below for more details). If you are going to bring in whole plants from the outdoors to the indoors, it is important to think about any pests you may be bringing into your home along with the plant and its soil. Always isolate these plants from your other indoor plants for a minimum of 3 weeks. Some people completely wash their plants in the tub, including the root ball, and pot them up in completely new potting soil when they bring them inside to reduce the chance of pest problems.
Once we have picked our herbs, either small bits throughout the season or large amounts at the end of the season, we need to think about the best way to keep them tasting fabulous for as long as humanly possible. Some herbs are at their best fresh and can taste completely different (and outright horrible) if dried. Cilantro and basil are prime examples. Freezing can be a great alternative for longer term storage of these delicate herbs. Alternatively, a few have even more flavour when dried (looking at you bay leaves).
Freshly picked herbs can be stored wrapped in a paper towel in a ziptop bag in the refrigerator for up to 3 or 4 days. Once you start to see dark mushy spots, it's time to toss the bunch. You can also stand herb stems up in a jar in the refrigerator with a loose plastic bag over top. This is a great way to store parsley, mint, and cilantro. Don't forget to change the water daily with this method. Remember, never wash your herbs until you are ready to use them! Washing before storage will lead to faster rotting.
The easiest way to freeze a small amount of herbs or any fresh, delicate herbs is in ice cube trays. Simply wash them, chop finely and freeze with about a tablespoon of water in your trays. Once frozen, remove them and store them in the freezer in a zip-top bag. They are very convenient to pop out whenever you need a splash of flavour. This method can also be used for pureed or minced root type herbs such as garlic or horseradish. No need to add water to those, although you might want to dedicate an ice cube tray specifically for these as the flavours can linger in plastic trays. You can also freeze whole bunches of herbs by placing them directly into a ziptop bag in the freezer. Scrunch the bag to break into pieces once completely frozen so you can remove a bit at a time whenever you need. Note that if you are going to be using herbs in a medicinal capacity, freezing can reduce or negatively affect those medicinal properties. Flavour will still be good to go.
Leaves and flowers are the most commonly dried parts. Conveniently, seeds are already in a form that is ready for dry storage. Once dried, your herbs can be stored in an airtight container in a cool dark place for about 1 year. Glass jars, such as mason jars, work well for this. Plus they allow you to watch for any moisture issues and appreciate their beauty at the same time. Do not store your herbs right beside your stove on the countertop! This is one of the worst places you can keep them. It is hot, humid, and often exposed to lots of light there. You can check for the freshness of your dried herbs by smelling them (they should still have a strong scent) or looking for colour loss.
To air-dry your herbs
wash herbs first and dry as completely as possible before drying (a salad spinner works great for this)
dry in a warm (but not hot) and dry location
hang your herbs in tied bundles of larger stems, or lay them out in thin layers of individual leaves and flowers on a screen (old, clean window screen works well, or baking racks for larger specimens)
this can take several days to a few weeks
To oven-dry your herbs:
set your oven for the lowest temperature possible (180 F is ideal)
lay your herbs in a single layer on a cookie sheet
place in the oven with the door open a crack for better air circulation
they will usually take a minimum of 45 minutes
check every 15 minutes or so. You don't want them to cook, only dry.
To dry your herbs using a dehydrator:
preheat to 115 F
place in a single layer on trays
label if you need, dried herbs can look very similar
they will usually take a minimum of 1 hour
check every 15 minutes or so and remove herbs as they dry (they can dry inconsistently between and within individual trays)
allow to cool before storing
To dry your herbs in the microwave:
wash herbs and spread leaves or flowers on a double layer of paper towel (don't use recycled paper towels as they can have tiny bits of metal that may spark in the microwave)
cover with an additional paper towel
cook on high for 1 minute
continue cooking with 20 second intervals, checking after each, until completely dry
this may take anywhere from 3 to 10 intervals
allow to cool before storing
see the article on Serious Eats for more details
How long your herbs take to dry with each method will vary between herbs and with how moist they are initially. You can tell your herbs are completely dry when they crumble easily between your fingers when rubbed. Spices such as seeds should be left whole and ground as needed to retain their flavour for as long as possible.
Garlic and onions need to undergo a short drying process called curing before being stored. Once they have been cured, they can be kept in a cool, dark pantry, cold room, or root cellar for many months. Once again, check out the article Garlic - The Stinking Rose for a curing -how-to.
Everyone is familiar with planting seeds, right? This is a method of propagation: creating new plants from existing ones. When you gather seeds from plants you have grown yourself, you create a self-sustaining cycle of propagation. We talked about collecting seeds above in the harvesting section. But there is another method of propagation that can be equally (and sometimes even more) simple. It's basically cutting off parts of existing plants, encouraging those pieces to grow roots and then potting up those small pieces as new plants. Which part of the plant you cut off will depend on the type of plant it is and how it grows best. Herbs with woody stems typically use semi-ripe cuttings (best taken in summer or fall) and those with tender herbaceous stems typically use softwood cuttings (best taken in spring or summer). You can easily take multiple cuttings from one specimen as they are both are taken from sideshoots of the main plant. There are other types of cuttings too, such as root, basal, eye, and hardwood cuttings, as well as pipings and stem sections, but we are going to concentrate on the easiest and most popular methods.
To root herb cuttings:
ensure plants are well watered before taking cuttings
choose a side shoot that is 3 to 6" long and cut it off using a very sharp knife or razorblade right below a node or leaf joint
remove the leaves from the bottom 1/3 to 1/2 of the cutting using your knife or razorblade, ensuring you don't damage the stem
dunk 1/4" of the cut end of your cutting into hormone rooting powder (not mandatory but helpful, especially for more stubborn herbs) available at any garden center
tap off any excess hormone powder
place cuttings into small containers filled with seed starting mix or soilless potting media (anything that is super light and very well draining will work)
water well and wait for new growth
once roots develop (you will see the tips start to grow rapidly) you can pot up your herbs into larger containers filled with regular potting soil.
The key to successful propagation by cuttings is to ensure they do not dry out at all during the process. That means you need to work quickly between making the cuts and getting them in the soil. You can also start your cuttings in water instead of soil. This works well for fast rooting herbs like mint and oregano. Simply transfer the cuttings to containers with potting soil once you see roots begin to form in the water (and don't forget to change the water every couple of days to keep it fresh). Kids love to watch this process up close! You can see exactly how to do this with our YouTube video on Propagating Culinary Herbs by this method here.
The final type of propagation for herbs is division. This is simply digging up the entire plant and either prying or cutting the root ball into 2 or more pieces. The pieces are then replanted as separate plants. This process works well for hardy perennial plants that don't have a tap root. Refer to the article Gardening in Calgary 101 to see detailed steps for plant division. Want to know what type of propagation works best for your herbs? Check out the next two herb articles (see links below). They will go into detail on each individual herb, along with the best way to propagate each one.
In The Kitchen
There are many ways to preserve your herbs by processing them directly in a finished product. Try these options for huge herb flavour any time of year.
Herb Salt: dried herbs can be blitzed in a food processor along with flakey or kosher salt (see Preserving Garlic Videos for a visual example)
Infused Oils: place fresh herbs into any oil and allow them to stand for approximately two weeks, strain out herbs (discard them) and bottle. Try any oil type you like (olive, avocado, canola, walnut, etc)
Infused Vinegars: same process as for oils, but using vinegar. Once again, try any type of vinegar (apple cider, balsamic, white, rice, champagne, etc).
Horseradish Sauce: puree chopped and peeled horseradish root with vinegar and salt in a food processor for a zesty addition to roast beef or other meats. Can be mixed with mayonnaise for a creamy version (see recipe link below)
Pesto: probably the best way to preserve fresh basil. Think outside the box and try other tender herbs instead of basil too. It can be frozen for extended storage (see recipe link below).
In general, when using herbs in cooking, we add dried herbs at the beginning of long cooking and fresh herbs right before serving for the best flavour. Fresh herbs will fade out if cooked for too long.
For a quick reference, here are some herbs to try that you can grow outdoors in our climate. Details for all of these herbs can be found in the next two herb articles. Experiment with any of these in your dishes!
Herbs to use for tea (fresh or dried): beebalm, chamomile, lemon verbena, stevia, lemon balm, anise hyssop, lavender, catnip, mint
Herbs for baking and sweets: lavender, beebalm, stevia, mint, sweet cicely, borage
Herbs for salads: borage, cilantro, fennel, nasturtium, parsley, chives, lovage, sorrel, chives, onions
Typical French herbs: parsley, sage, rosemary, thyme, bay, tarragon, fennel, chervil, lavender, chives, lovage, sorrel, garlic
Typical Mexican herbs: cilantro, coriander, epazote, perilla, garlic
Typical Italian herbs: basil, marjoram, oregano, rosemary, garlic
Typical Eastern European herbs: dill, caraway, parsley, mint, sorrel, savory, horseradish, garlic
Typical Asian herbs: basil, cilantro, chives, mint, garlic
Typical Indian herbs: cilantro, coriander, curry plant, fennel, mint, hyssop, garlic
Yummy gardening everyone!
Recipes That Feature Herbs
Horseradish Sauce (recipe coming soon)
Homemade Pesto (found in the recipe for Speedy Pesto Chicken Soup)
Garlic Salt, Minced Garlic, and Garlic Butter (found in the article Preserving Garlic Videos)
Lacto Fermented Garlic and Honey Fermented Garlic (found in the article Preserving Garlic Videos)
plus more to come!
Further Reading and Resources
Pursell, J.J. "The Herbal Apothecary" 2015 Timber Press, Portland, Oregon, USA
Keville, Kathi "Herbs An Illustrated Encyclopedia. A Complete Culinary, Cosmetic, Medicinal, and Ornamental Guide" 1994 Friedman Publishing Group, New York, New York, USA
Helmer, Jodi "Growing Your Own Tea Garden. The Guide to Growing and Harvesting Flavorful Teas in Your Backyard" 2019 Fox Chapel Publishers, Mount Joy, PA, USA
Reader's Digest "The Essential Book of Herbs. Gardening. Health. Cooking." 2021 Trusted Media Brands, New York, USA
Clarke, Graham & Toogood, Alan "The Complete Book of Plant Propagation" 1992, Ward Lock Limited, Wellington House, London, England
Richters (www.richters.com) for the absolute largerst selection of herb seeds, plugs and herb related products.