The lowdown on lights

Departments - Straight Talk | Honest insights from an IGC expert

Help customers work around the constraints of natural lighting and successfully venture into indoor edibles with these tips.

March 11, 2021

Educate your customers about the different light requirements for the edibles they plan to grow.

Want to grow edibles indoors? So do a lot of our customers! With the excessive time we have all been spending cooped up over the past year, it is no wonder so many home hobbyists want to bring the veggie garden indoors. There is no reason home growers should let the weather, or limited outdoor space, keep them from growing at least a little food indoors any time of the year. Indoor temperatures are typically suitable for growing many types of food, even during the coldest parts of winter. Where most home growers fall short, however, is the amount of light they have in their space.

Customers who desire to branch out from indoor houseplants to indoor food need to learn some basics about natural and artificial lighting. That means your staff does too. The average home windowsill generally offers up low light volume, especially in winter when natural light levels are low and day lengths are short. If you want to germinate strong, vigorous seedlings or grow sun-loving leafy and fruiting plants, grow lights are usually in order.

Spice it up

Herbs are always a popular category with home growers who want to garden indoors. Up until recently, most questions posed to me about growing edibles indoors revolved around herbs. Bringing a bit of the kitchen garden to the kitchen counter with a few fresh herbs seems like a manageable task for most of our customers. Most do not have enough natural light in their homes to sustain healthy vigorous herbs for a regular harvest. The most popular herbs are sun-loving; basil and thyme will need high levels of light indoors to thrive.

Tiny plants, big flavor

If your customer is trying to grow kitchen herbs in a self-contained growing unit, such as the small hydroponic units with grow lights that are out on the market, guide them to dwarf cultivars. Most of those small grow units provide just barely enough light for such herbs, but more importantly do not provide enough space for standard size herb plants to grow. What is the solution? Smaller plants!

Guide your indoor growers to dwarf herb cultivars that are easier to grow in smaller spaces.

Basil ‘Spicy Bush,’ ‘Pluto,’ ‘Piccolino,’ ‘Dwarf Greek’ and ‘Spicy Globe’ are perfect for small grow units or for growing on smaller light shelves; but their tiny leaves still pack a big flavor. Parsley ‘Extra Curled Dwarf’ can replace bulky parsley types.

While standard oregano plants can get quite beasty, Oregano ‘Nanum’ and ‘Betty Rollins’ are perfectly tidy for tight spaces. Most types of thyme are compact already, so there are no space issues there.

Fast harvest

With the pandemic putting a big focus on health and wellness, the interest in growing microgreens is surging. Microgreens are perfect for space-challenged growers. You only need a square foot or so of space and either bright light from a southern window or a small grow light in the 20-watt range. Cool-season herbs, such as cilantro, are quick to bolt indoors. I usually recommend growing them as quick harvest microgreens instead.

I think the biggest challenge for customers this year when it comes to growing microgreens may be sourcing seed. Pandemic gardening has also put huge pressure on the seed-producers, so it may be tough to source enough seeds.

After herbs and microgreens, many beginners may want to dig into growing larger greens. Many varieties of lettuce, kale, mache, watercress, sorrel and spinach will grow in medium light levels and can be grown with lower intensity grow lighting.

Indoor strawberry growing is a great way to get kids involved in home gardening projects.

Bearing fruit

Sun-loving fruiting plants, such as tomatoes, peppers and citrus, will need the highest levels of light indoors. I do not recommend trying to grow these crops without higher intensity grow lights. This is also where grow tents can come in handy. I grow my tomatoes, peppers, cucumbers and the like in my garage over the winter in grow tents.

With bigger fruiting plants, space becomes an even bigger issue. So again, I recommend starting with dwarf cultivars. Many of the new micro-tomatoes can be grown on standard grow light shelves or in the self-contained grow units. They require less light volume than their big slicer cousins but still deliver nice handfuls of cherry tomatoes. Compact peppers, bush beans and dwarf pickling cucumbers are all perfect for the indoor vegetable garden.

Trend alert

A new trend I have observed recently is an increased interest in growing berries indoors — strawberries, specifically. Many parents are looking for indoor gardening projects they can do with their kids and kids want strawberries! If your customers want indoor strawberry growing advice, guide them to day-neutral (everbearing) cultivars that will fruit regularly without manipulating photoperiod. I personally prefer to grow Alpine strawberries indoors because of their compact size and amazing flavor.

If your customers are ready to dig into indoor food gardening, help them match their light levels, space and experience level with the crops they grow. Indoor food growing is not only a growing category, but one that has no seasonal limits!

Leslie (CPH) owns Halleck Horticultural, LLC, through which she provides horticultural consulting, business and marketing strategy, product development and branding, and content creation for green industry companies.