Planting and Transplanting

This page consists of overviews of common procedures for planting seeds and small plants.

Direct seeding (planting in soil)
When planting seeds directly into the soil, a good rule of thumb is to bury the seed at a depth which is three times the diameter of the seed. Large seeds are planted deeper than small seeds.

Different types of plants will have different recommended seeding rates/spacing. Typically, the seed package will include a number of inches or feet suggested between seeds.

Some plants, like cucurbits, are planted in "hills" of three or more seeds a few inches from each other, with 3-5 feet between hills. Other plants are planted at some even interval, such as 6 seeds per foot.

Often times these rates reflect a closer spacing than is ideal for the mature plants. This is because germination is not 100% successful and some plants are not as vigorous. Conventionally, more seeds are planted than plants desired and after the seedlings have been established they are "thinned" to give the best looking plants more space. There are tradeoffs here, however. Space can be more effectively used if "blocks" of area are seeded rather than rows. This minimizes erosion and increases the number of plants per area. However, it can be challenging from the point of view of removing non-crop plants which compete for sunlight, water and nutrients.

More densely planted plants will often not achieve the same size as their conventional counterparts, but because inter-row space is used more efficiently the possibility of greater yield per area can be realized assuming water and nutrients are not limiting and the crop plant adequately suppresses undesirable plants.

Making potting media
Potting media is comprised of various non-soil materials such as: peat moss, coconut coir, perlite, sand, compost, worm castings, vermiculite.

Different ratios of these materials confer different physical and chemical properties to the media.

Seeding in flats (greenhouse)
Certain plants, especially those which require a long growing season with warm temperatures, are best sown indoors before being moved outside.

Seeds should be planted shallowly in order to maximize the depth of the cell that can be populated by roots. Roots generally will only grow downwards (a form of gravitropism). For example, if you plant a seed halfway down inside a container, only the bottom half will be available for the new roots to grow into which limits plant growth and wastes valuable media and greenhouse space. Care should be taken to ensure that newly seeded flats stay moist to ensure that seeds germinate to their maximum potential.

Up-potting
When a plant has outgrown a given container, but is not yet ready to be transplanted outdoors, up-potting may be in order. Up-potting is simply transplanting a plant from a small container into a larger container. When the roots have fully populated a given container, the plant will often benefit from greater space to spread out. A plant which is too large for its container may run into nutritional deficiency or consume its water much faster, leading to drought stress. There is also a trade-off between plant size and total number of plants which can fit in the greenhouse which needs to be balanced.

A plant can be carefully removed from a container by gently putting pressure on the walls of the container to loosen the potting media. To remove the plant, invert the container with one hand, using the other to prevent the plant from falling, or by gently pull up on the stem. Be careful not to rip the plant by pulling too forcefully which will damage the roots and may decrease the plants likelyhood of survival.

After a plant has been removed from its old container, many plants benefit from having the roots around the outside to be loosened up. These roots normally would have grown outwards, but due to the constraints of the container wind up being wrapped in circles. Gently brushing around the outside of the root ball with the fingertips or rolling the rootball between two hands will be sufficient to allow the root tips to quickly grow outward into the new media of the larger container.

Transplanting
Ultimately, plants which are grown in the greenhouse will need to be moved outdoors.