Lettuce is best when harvested minutes before eating.  It’s crisper, more flavorful, and is more nutritious than lettuce you buy, which is normally a week + old. These will also be the fastest-growing plants in your indoor edible garden – as long as you give them enough water, nutrients (and enough light too, of course). In this blog, we’ll go over what they are, your planter options, and how to take care of them for healthy, productive plants.  

Growing Lettuce & Leafy Greens indoors

This group consists of Head Lettuce, Leaf Lettuce and other greens (like Kale, Arugula, & Celery). The leafy greens are called “Cool Weather Crops” because outdoors, they’re the first to grow after winter and they make seeds by mid-summer. However, this speed also means they have a short growing season. Combined with their susceptibility to pests (snails and critters love their large soft leaves) means they just grow better, longer, and more consistently indoors. 

What’s the best planter for Lettuce & Leafy Greens?

Free Draining Pot vs Self Watering Planter

These plants like consistent, moist soil. If you’re good about daily check-ups, feeling the soil moisture, and adding water as needed, then a simple pot can work well. If you’re like most of us, and are better with a weekly routine or don’t know how much water to add, a self-watering planter is really helpful. Beyond fitting into our lives better, they keep more consistent soil conditions for the plants. So for practicality and productivity reasons, we recommend going with a self watering planter over a free draining pot for all leafy greens. 

The roots of these plants are resistant to root rot so they can work in all types of self watering planters. We still recommend going with a ceramic based self watering planter for its precision, cleanliness, and flexibility to grow whatever you want, but these plants should also work in the boggy soil of wick-based planters. 

Self Watering Planter vs. Hydroponics

As these plants like wet soil, they can also all grow hydroponically – where the roots grow directly into nutrient enriched water. Hydroponics come in all shapes and sizes, but they typically have a pump to move water and need a special type of nutrients, so they tend to be more expensive. Also, most plants grow just as well (if not better) in consistently moist soil, so most of the time we don’t find hydroponics to be worth the extra complexity.  However, lettuce, in particular, can grow twice as fast in hydroponics so if maximizing your growth is important, it’s worth the investment.

How to Grow Leafy Greens in a Ceramic Self Watering Planter

The instructions below are most relevant to our upcoming Self Watering Planter that could be released summer 2021. There are a couple of current options on the market,  including Wet Pots, COSWIP, and the Great Northern. Of these, the Wet Pots keep the best soil moisture levels for leafy greens.

How to fill the Self Watering Planter

The ceramic material used in different planters lets in different amounts of water, but the wetness of the soil will be directly proportional to how high you fill the reservoir.  Other factors like how big your plant is and how much light it gets will impact the level that you’ll want to fill the reservoir to – so it’s best to pay attention to the soil. With leafy greens, you want to keep the soil fairly wet. Start by letting the water drop down until the top ½ inch of soil is dry – this is your “low fill” line. Fill the planter to the top whenever it goes below this mark.

What type of planters & soil should you use?

Regular potting mix is made for these types of plants – it works great! When starting, we recommend adding an initial charge of balanced slow release fertilizer, following the manufacturer’s recommendation that will help feed your plant for the first 3 months.

When should you add fertilizer?

These plants are moderate to heavy feeders – they grow quickly so need additional nutrients to replace what they use. As they are mostly growing leaves they prefer a High-N fertilizer.  If you start to notice pale leaves or slower growth you should add more fertilizer. You can use water soluble (every 1-2 weeks), granular (4-8 weeks), or slow-release (10-14 weeks) following the manufacturer’s dose. If you are using a liquid fertilizer, be careful to not get it on the plant leaves. 

Companions

These plants picked the most nutrient rich place to live – so they’re accustomed to having close neighbors.