No matter what their size or style, potted herbs growing on your deck, patio or porch bring an extra dimension of beauty to outdoor spaces with their lively colors, fragrances and textures. You'll also love having sprigs of your favorite culinary herbs within easy reach of the grill or just outside your kitchen door.
Growing herbs in containers solves just about any gardening problem. And they are amazingly easy to grow as you can provide the ideal conditions for almost any plant, regardless of your garden's size or natural conditions.
There's no better time than now to begin filling your outdoor living space with fresh flavor, fragrance and color. Here are 10 essential tips to keeping your potted herb garden vibrant and lush from early spring through fall.
1. Plant selection
You can grow practically any herb in a pot as long as you have the right container and potting mix. Some herbs are particularly suited to growing in pots.
Most culinary herbs are great choices, especially familiar favorites like basil, chives, oregano, parsley, rosemary and thyme. Pots allow you to contain the characteristics of mint, lemon balm or other aggressive herbs that exhibit invasive tendencies in your garden.
Tropical or tender herbs such as lemon grass (Cymbopogon citratus) and scented geraniums (Pelargonium spp.) are ideally-suited because you can bring the pots in a sheltered area or indoors to overwinter. And specimen-type plants like lemon verbena (Aloysia citrodora) and sweet bay (Laurus nobilis) add moveable focal points of interest.
2. Pot pointers
Herbs can be grown in just about any type of pot or container as long as it has sufficient holes in the bottom so surplus water can easily drain away. Your options are nearly endless, with pots that are available in a variety of styles, colors, sizes and materials.
Plastic pots are lightweight and inexpensive, but they can deteriorate over time in outdoor conditions. Heavier ceramic, stone or cement containers are durable and nearly last a lifetime, but they are often heavy and difficult to move. Clay pots are porous and therefore dry out quickly, which makes them well-suited to growing Mediterranean herbs such as thyme. However they are breakable and subject to damage from hard freezes.
That said, it's best not to plant a permanent display in a plastic pot, a moisture-loving herb in a clay pot, or a tender herb that needs to overwinter indoors in a large and heavy stone container.
Use a lightweight and porous potting mix when planting herb--like this rosemary--in containers.
3. Soil essentials
Garden soil is too heavy for use in containers and lacks the porosity needed to grow healthy potted herbs. Using a lightweight and porous commercial potting mix is essential to growing any plant in a container. The potting mix needs to retain moisture, yet drain easily--otherwise the roots become deprived of oxygen, causing the plant's demise.
You can use a high-quality commercial potting mix straight from the bag. But if you really want to get your herbs off to a great start, create a custom blend by mixing together the following: three parts potting mix; one part compost, earthworm castings or aged manure for added nutrients; and one part perlite, pumice or coarse sand for added aeration and drainage.
4. Pair the right herb with the right size pot
As a general rule, pots as small as 10 inches in diameter and larger can be used for single herb plantings; a minimum of 18 inches in diameter is needed when growing large specimens, multiple herbs in one pot, or culinary herbs that you wish to cultivate frequently for kitchen use. Also make sure that pots are deep enough to accommodate growing roots--remember that bigger pots equals bigger plants.
5. Pairing up plants
When creating multiple plant displays, make sure to pair herbs with similar light requirements and water needs in the same pots. Allow enough space between plants so they all have room to grow and thrive. Remember to space according to the plant's mature size: smaller plants like dwarf basil can be spaced closer together than, say, rosemary or comfrey.
6. Get creative on pot placement
Potted plants are quite portable and can do more than dress up your patio or deck. Use potted herbs to border a path, enliven an outdoor dining area, create movement when staggered on steps, or to fill the seasonal gaps in beds and borders. Add sensory appeal right outside your door by grouping containers of culinary herbs arranged at various heights. For example, you can place some pots on bricks, some on decorative pots turned upside-down, and some on a bench, chair or table.
7. Water wisely
Water needs vary according to the plant's need for moisture as well as the pot's size, type, location and time of year. Let the potting soil dry slightly between waterings for Mediterranean and other drought-tolerant herbs; keep the mix slightly moist at all times--like a wrung-out sponge--for basil, chives and other herbs with moderate to average moisture needs.
The best way to tell when it's time to water is to let your finger be your guide. If the soil feels dry 1 to 2 inches below the surface, then it's probably time to water. When you do water, be sure to water thoroughly until you see water flowing freely from the pot's drainage holes.
8. Feed lightly
Plants growing in the ground have ample room to send out their roots in search of nutrients. The roots of herbs grown in containers are much more confined. As such, it's best to feed plants lightly with a slow-release organic fertilizer, or a half-strength solution of organic liquid fertilizer such as fish emulsion, kelp or compost tea. Feed plants during the growing season every three to four weeks with a liquid fertilizer, or apply a slow-release organic fertilizer one to three times a year.
9. Provide good drainage
If your pot lacks sufficient drainage holes, you can always add more. Use a masonry bit to drill holes in clay, ceramic, stone or earthenware containers. Elevating pots on pottery feet, bricks, stones or even an upside-down pot also helps improve drainage.
10. Pinch and prune
Pinching faded flowers and leggy stems will encourage more blooms and strong, new growth. The result will be a bushier and more productive plant so you can snip those flavorful sprigs and flowering stems to enjoy in the kitchen.
--Kris Wetherbee