As seen in: Issue 03

Garden Indoors: A Good Start

When you garden indoors, productivity requires good practices and techniques from the beginning. Abundant harvests from any herb, fruit, or vegetable plant depends on seed quality – and everything that happens during each of its growth stages. Even in your outdoor garden, excellence is never the result of inferior materials or shoddy workmanship. Remember that, and deliver perfect conditions from the very start.

Always obtain seed from reputable sources. An established seed house is best. Your seed will be fresh and come from disease-free plants. It will also be handled and stored properly to make sure the best germination results are possible. Stick with suppliers who have signed the Safe Seed Pledge as your GMO-free source for garden seed. Check out the Council for Responsible Genetics.

A seed is a dormant embryo. Each one comes packed with the knowledge the new plant needs to grow roots, leaves, flowers, fruit and set seed to continue the species. Powering it up requires only consistent moisture, air and the right temperature. It comes with its own start-up energy source. They need no fertilizer or nutrients during the germination stage. Light isn’t even needed for the first week or two (sometimes less with seeds that germinate faster).


A plant’s idea of the gray area between right and wrong is a pretty slim window. In the garden indoors, you can’t blame poor germination on thieving birds and squirrels. If your seeds don’t germinate, either you have not purchased quality seed, failed to monitor environmental conditions, or ignored this particular seed’s needs. There are cool season and warm season plants. Understanding this is important. Before you get started, you need to create the perfect season for your selected crop. Cool season plants grow beautifully in an
environment that will send warm season plants like tomatoes into a sickly tizzy. You can grow both types simultaneously with separate germination chambers and grow rooms. You can’t force a plant’s vigor in the wrong conditions. It leads to weak plants, climatic disease issues and poor harvests… or total failure.

Maximizing your harvest while reducing costs starts with discovering your seeds’ needs for germination and providing the best circumstances. Seeds sprout in cooler conditions than for flower and fruit stages. It’s Nature’s way of protecting their fragile parts from more intense sunlight and long, hot days. Maintaining the proper temperature is easily done with a heat mat beneath your germination chamber. This will allow for faster, more robust and uniform development. Do invest in a grower’s mat with a thermostat to avoid cooking your seeds or sprouts.


Unlike planting outdoors, you want thoroughly moistened media for seed start when you garden indoors. There are a variety of materials you can use, dependent on your growing system. Some people swear by the wet paper towels enclosed in a plastic baggie routine. Handling just sprouted seeds is a delicate matter. You run the risk of breaking or damaging the fragile young root or shoot. You don’t have to work this hard or introduce such intricacy to getting a grow going.

Jiffy peat pellets (a.k.a. pucks) aren’t your best option. Issues include slow germination and root growth, poor air flow capacity and high acidity. Finally, it is the nature of peat moss to tie up nitrogen. Thinking of using Jiffy peat pots filled with potting mix? Wood pulp added to their composition increases this removal of nitrogen for breaking down. There is also a danger of peat pucks holding too much moisture causing rot, diseases or damping off.

Rockwool starter cubes or propagation plugs commonly used in hydroponics offer a perfect balance of air, moisture and drainage. Sprouting varies by seed type and takes 2-8 days. Consistent saturation and a pH level of 4.5-5.5 is needed (dependent on seed type) and accomplished by soaking the cubes for 24 hours. Chlorinated tap water can harm sprouting action. Use distilled water or mineral water instead. Adjust the soaking solution’s pH level to correct your water’s pH and that of the rockwool’s alkalinity. Do this by slowly adding acid solution to lower pH or alkaline solution to raise it. Measure the water pH until you meet the desired level for the plant type. Put your prepped rockwool starters in a standard nursery tray with a dome. Sow the seed at the required depth. Keep the covered tray in a warm, moist place until vegetation appears.

Note that proper temperature ranges are generally only 5-7 degrees apart. Five degrees might not seem like much, but you aren’t a plant. Deliver the happiness zone. Seed starting mixes shouldn’t have huge chunks of material. It should hug your seed loosely without leaving large tunnels exposing the seed or roots to too much air. Mist if you must moisten again soon after sowing. Overhead watering causes light media and seed float resulting in losing planting depth and central placement. For small seed at a shallow depth, this could mean failure to sprout due to ending up on top of the media.


Most seeds grow best when covered with media to their preferred depth, though some seed types can do well on the surface with enough moisture. Plant too deep or too shallow, and your germination success is doubtful. Don’t guess – read the seed packet. The purpose of planting depth ensures that the seed can absorb enough moisture to activate. A seed must absorb 50% of its weight in moisture to germinate. Poor drainage, improper planting depth, and loss of moisture due to evaporation are all things you can’t allow to happen if you are going to eat. Depending on what you want to grow, it can vary from 1/8 inch to a full inch or more. As a rule of thumb, fine seeds need a shallow depth, while large seeds get planted deep.


All the nutrition new sprouts need is in the cotyledon. Just because you have signs of life, doesn’t mean it is time to feed. Patience. You need robust root systems for an optimum harvest, which develop at this stage. Seedlings are fragile, and even a weak nutrient solution can burn leaves and roots, as well as make them focus on producing top growth. Don’t mess up their programming!

If you continue to supply enough pH balanced water, your new plants will swiftly send roots down deep and in all directions seeking a food source. The harder they search, the more developed the roots will become. Nature provides plenty of nutrition with the seed to fortify young plants until they reach the vegetative stage of growth.

Grow Lights Give Best Results To Garden Indoors

Tomato seedlings stretching to find enough light. Courtesy of Rudy Kleysteuber/Flickr


Once small seedling leaves appear, plants start reaching to find sunlight. Remove the dome and get your seedlings under lights right away. Cover all roots to prevent damage and support rapid growth. If you don’t act fast enough, they will stretch and get leggy searching for the sun – like those bending tomato plants above – leading to less robust plants and harvest. Give them 12-16 hours a day under CFL lamps. The heat of HID grow lights will overheat or fry tender seedlings.

Closely monitor temperature and moisture. In 10-14 days actual leaves and rooting through the bottom of your media are present. It is time for transplanting. Your young crop has entered the vegetative stage. Now they need intense light, growing temps, and nutrients in the indoor garden.

Similar articles

Growing Guide: How To Harden Off Your Plants

One of the most crucial roles you play as a grower is hardening off your plants. If done properly, you’ll be well on your way to a successful harvest!

Leave a Comment

Your email address will not be published. Required fields are marked *


Tammy Clayton

Contributing Writer at Garden Culture Magazine

Tammy has been immersed in the world of plants and growing since her first job as an assistant weeder at the tender age of 8. Heavily influenced by a former life as a landscape designer and nursery owner, she swears good looking plants follow her home.