Transplanting Marijuana Plants: How to Do It Safely

Marijuana plant seedling
June 08, 2020

The ability to transplant marijuana plants is an essential string to every cannabis grower’s bow. Relocating young plants to larger pots allows them to continue growing through both the vegetative and flowering stages. It also prevents plants becoming root bound and unable to take in nutrients, water and oxygen

Transplanting, though, is a delicate process and it can be just as stressful for the plant as it is for the gardener. Transplant shock or accidental damage can lead to stunted growth and (in extreme cases) the death of your plants.

Once you know how to transplant your marijuana plants safely, they should be able to grow an extensive root system with a larger plant mass. And you know what that means: bigger, better weed!

Firstly, let’s ask ourselves some common transplanting questions (and maybe answer them, too)… Can you transplant autoflowers? When do you transplant cannabis plants? Can you transplant cannabis more than once? How do you choose the pot size? How do you transplant cannabis according to the size of the plant or the stage of the grow? Let’s find out!

Transplanting Marijuana Plants: A Guide

Can you transplant autos? Simple answer: no. You should not transplant any strain grown from auto-flowering seeds. Of course, if you started your auto in a tiny pot or a solo cup, you’ll need to move them to their final pot, but this will be the ONLY time you should transplant your autos.

Autoflowering strains are generally easy to grow and reach full maturity around 10 weeks from germination. With such a rapid growth rate, you’ll be harvesting buds much earlier than those grown from other types of seeds. This fast growth means your autos have less time to recover from severe stress and injuries, such as might be caused by transplanting errors.

Photoperiod feminized and especially regular seeds, on the other hand, can handle the stress of transplanting. All photoperiod strains (even the Fast Versions) can be transplanted to temporary pots before being moved to their final containers.

When do you transplant cannabis plants?

The main things to consider when transplanting cannabis are timing and growth stage. Using small pots during the seedling stage makes the plants easier to manage. Once they enter the vegetative stage, they need to be moved to a temporary or final container. In between these stages, you should use pots appropriate for the plant’s growth and size.

If you transplant too late, the plant will start outgrowing its container. The roots, having no extra room to grow, become rootbound.

What are the symptoms of a rootbound weed plant?

  • Soil drying out too fast
  • Wilting
  • Drooping
  • Discoloration or unusual spots on the leaves
  • Sudden stretching
  • Reddening of the stems
  • Roots appearing above the soil

You might also notice the containers starting to tip over as a result of the plant being too tall and heavy.

When do you transplant cannabis seedlings?

Once you have successfully germinated your cannabis seeds, your seedling will spend its early weeks in a solo cup or small pot. Usually, seedlings can be transplanted 7 to 10 days after germination. This should give you a good idea of when to transplant seedlings, depending on the growth characteristics of specific strains.

A more accurate way of knowing when it’s time to transplant is to look for visual cues. One sure-fire cue is the number of real leaves – four or five sets usually means it’s time to transplant. The first tiny leaves that grow from the sprout – called cotyledons – do not count.

Another indicator is leaves growing beyond the edges of the pot. This means the plant is getting too big for the starter cup or small pot.

Monitoring the root system also helps. Check the drainage holes at the bottom. The roots should appear white and healthy. Any discoloration or darkening indicates that the plant is rootbound. If so, transplant right away.

When do you transplant during the vegetative stage?

If your seedling is in a temporary pot, it will eventually grow too large and need to be moved into its final container.

Some people perform the final transplant two weeks before transitioning to the flowering stage. During this time, when the growth rate is explosive, a larger container will be needed to accommodate the expansion of the stems, leaves and roots.

You can delay or even forget transplanting if the temporary pot is large enough for the entirety of the vegetative stage.

If you’re raising “mother” plants for cloning, you might need to transplant every so often to keep them in the vegetative stage. Let the plants maximize the space in the current pot before relocating.

How do you choose pot size when transplanting cannabis?

Transplanting means moving plants to a bigger container. The question is, how big?

For seedlings, it should be double the size of the old pot. 1-, 2-, or 3-gallon ones are the most common. Depending on the strain, you might have to transplant once more later in the vegetative stage, unless you opted to go straight to the final container. In this case, you’ll do just one transplant throughout the grow.

In general, marijuana plants require two gallons of soil for every twelve inches of growth. You should also factor in the potential height of the chosen cultivar when choosing the pot size.

Final Plant Height Recommended Container Size
12″ 2 to 3 gallons
24″ 3 to 5 gallons
36″ 6 to 8 gallons
48″ 8 to 10 gallons
60″ 12 gallons or more

Indoors, the final container is usually 3- to 5-gallon pots. Outdoor plants, on the other hand, typically need more than five gallons. These are just estimates, though. It all depends on the physical traits and growth patterns of the strain.

How do you transplant cannabis?

Transplanting cannabis plants is about being well-prepared and following the correct procedures. Preparation is key: you don’t want to lift out the root ball only to discover the new pot is still at the store.

What do you need to prepare before transplanting cannabis?

There are some things you need to do before getting started, things that can be a massive influence on the success or failure of your transplant.

First, keep the growing area clean and sanitized to prevent contamination and wash your hands thoroughly with soap and water before touching the plants. As an alternative, you can wear gloves.

Roots are sensitive: handle them with care.

How do you transplant cannabis seedlings?

Transplanting seedlings should be done with slightly moist (not saturated, not completely dry) soil. This makes it easier to handle and remove from the container.

During the day of the transplant, fill the new pot with high-quality soil or soilless mix. Leave a gap of about 2 inches from the top to prevent water from overflowing. Drench the medium to dampen it, making it more absorbent.

Dig out a hole at the center of the soil using a handheld shovel. The hole should have the same diameter and depth as the old pot.

Avoid intense light inside the grow room – this can increase the risk of transplant shock.

How do you transplant vegetating plants?

Before transplanting, prepare the new container. Fill it with the desired medium to about halfway. Make sure there’s enough room to hold the soil volume from the previous pot. Pat it down gently.

Water the plants you’ll be moving. Let them dry for a couple of hours. A wet medium could break apart and get damaged during the transplant.

Transplanting seedlings: step by step

Note: we will use soil in this example but the steps are the same for most growing media.

  1. Prepare the new container by filling with soil and creating a cavity for the new arrival.
  2. Ready the seedling. Run a thin blade inside the edge of the starter cup; this will make it easier to detach the roots from the sides of the container.
  3. Gently place your hand on top of the soil. Position the stem in between the fingers. Tighten your grip (a little).
  4. Tip the pot upside down in a gentle and controlled matter. Gently slide out the rootball. It should ease out slowly and steadily.
  5. Place the plant in the hole formed in the new container (see step one).
  6. Add a little soil to help keep the plant steady and upright.
  7. Compress the soil around the roots lightly. Ensure that it is flat and even.
  8. Water the young plants immediately to avoid stress. A small volume of water will do.
  9. Observe the seedlings for the next few days. Watch out for any symptoms of transplant shock. If you do spot signs of shock, try feeding a little liquid kelp meal – this should help with the healing process.

Vegetative transplanting: step by step

  1. Prepare the new pot.
  2. Ready the plant. Hold the base of the stem in one hand and the base of the pot in the other.
  3. Slowly tip the plant upside down. Pull it out carefully until the full root ball slides out.
  4. If you have timed the transplant correctly, the root ball will retain the shape of the pot.
  5. Seat the plant in the new container. Add some extra soil to fill any empty space.
  6. Larger cultivars might need stakes for structural support. Keep until the plants are stable and standing upright.
  7. Feed the plants with a light dose of nutrients to help them transition to their new home. To prevent stress and shock, you can also lower the intensity of the lamps temporarily.
  8. If you transplant in the late vegetative stage, wait for at least one to weeks before triggering the flowering phase.

Transplanting cannabis is pretty straightforward, provided you’re prepared and your space is clean and uncluttered. Don’t be too rough with the plants, don’t pull them out using anything but the base of the main stem. Don’t ignore the plants after transplant. Treat the first few hours and days as is your plant is in intensive care – observe them for signs of shock or damage and take appropriate action where needed.