If you have ever propagated plant cuttings in water, you must have noticed that they easily die soon after they are transferred to the soil or vice versa.
How to convert cuttings from water to soil without killing them?
The best way to help a plant or cuttings replace their water roots with soil roots is to add a solid substrate, such as sand or fine gravel, that does not absorb water and float, and slowly remove the water over 2 weeks and let it evaporate naturally. Switching from soil to water substrate is similar but not all plants can adapt.
In this article, we will go through the procedure of converting cuttings from water to soil, and vice versa, step by step. Let’s get started.
1. Differences between water vs soil substrate
The major difference that a plant or cuttings have to adapt to when being transferred from a water substrate to a soil substrate is in the oxygen level.
Soil roots are made to absorb water and oxygen from the air pockets among the soil particles.
But when soil roots are submerged in a low-oxygen environment (e.g. in water), they will rot because of a lack of oxygen. For plants that can adapt to such an environment, they will have to grow a set of water roots with special mechanisms to breathe through the leaves and prevent oxygen loss from the roots.
Read this article to learn more about the difference between water roots and soil roots.
It is thus difficult for established plants to replace their water roots with soil roots, or vice versa when there is a change of substrate. It is easier for cuttings to adapt to the new substrate.
The easiest way is to transfer the cuttings from water to soil as soon as you see the first sign of tiny roots (only 1 to 2 mm) poking out of the lenticels (noticeable pores on the stem). You would not wait until the water roots have been established extensively before you transplant them.
Although this method is not exactly converting one set of roots to another, this is the least stressful for the plants as it reduces the shock of switching the growing medium and breaking roots during the process.
Another method is for plants or cuttings with established, long water roots and it would require you slowly acclimatize the cuttings to soil conditions.
1. Prepare small individual containers (best if transparent for monitoring) with some water for each plant or cutting.
2. In the water-filled containers, add coarse sand or fine gravel (anything that would not absorb water and float) until the roots are covered. Alternatively, you can add wet potting mix and put some pebbles to weigh it down.
3. Pour or scoop out a small amount of water, around 1 tbsp per cup (250 ml), every other day over the course of 1 to 2 weeks. Let the water evaporate and decrease slowly and naturally, until the plant or cuttings adapt to the soil-like substrate. Make sure that the new substrate is moist, but not waterlogged.
4. Leave them in the shade for a week.
5. Do not use any fertilizer during this period to prevent burning the roots until at least a few weeks later, or until it has fully adapted to the new substrate
6. After 2 weeks or so, you should see yellowish soil roots growing through the sand or soil.
7. When new soil roots have grown, carefully scoop out the now rooted plant along with the soil from the original container, and transplant it to a bigger pot with sterile potting soil.
If you use garden soil instead of sand or potting mix, you will need to sterilize the soil first to get rid of any pathogens. That can easily be done by putting it in the oven for 20 minutes at 212 F (100 C).
When to transfer plants from water to soil?
The best time to transplant a plant or cuttings from one substrate to another is during its active growing stage usually in spring, with obvious new growths like new leaves or gaining height.
Another good time to change the growing substrate is when root tips first come out of the lenticels (pores) of the stem.
For plants with established water roots, it would take longer to adapt to a new substrate.
In the case of monstera, it can take up to two months before your plant is ready to move into the soil. Monstera roots aren’t as fast to emerge or grow as other plants like mint or basil. But with adequate light and warmth, the roots start to grow around two weeks after putting the cutting in water. In about two months there should be enough roots and some new growth, and you can move the plant at this time.
Pothos (money plant) is another one that roots well in water and can even grow indefinitely in water. They are similar to monstera plants with roots that take some time to emerge, usually around 10 to 12 days. By the second month, there should be many roots of sizeable lengths, so that you can safely start moving the plant to the soil.
Converting plants from soil to water only works for plants that are tolerant of the low-oxygen environment in water, such as Monstera, Potho, African violet, Spiderwort.
Even for these plants, it’s best to start plants in water and have them continue that way. Converting soil roots to water roots is stressful for any plant.
But if you must move your plants into the water, here’s how to do it.
- Remove the plant from the container
- Gently break off any soil held in and around the root ball. You need to be very careful not to damage the roots, damaged roots will make the transition harder.
- To clean the roots without having to touch them or damage them, clean the roots under water to rinse off any remaining dirt on the roots. The water shouldn’t be too cold, if possible, it should be lukewarm.
- Get a container that’s about the same size as the one the plant was in before. The container doesn’t need to be transparent, but with transparent containers, you can see how the roots are doing.
- Use clean shears to trim off the leaves, leaving just one or two behind to allow the plant to focus its energy on root development rather than foliage.
- Put the now trimmed plant in the water, and position the container in a warm area with adequate indirect sunlight.
- Don’t disturb the plant for the first few days. This will give it time to get used to its new home.
- On the fourth day, you can change the water but do it carefully, if possible do not disturb the roots.
When is the best time?
The best time to move plants from soil to water is during the growing season in spring. The temperature is warm, and the plant is actively growing so it is better able to handle the stress of moving into a totally new environment.
How long does it take?
Just like with converting water roots to soil roots, the time it takes depends on the plant. But generally, it should take 2 to 4 weeks before you start seeing any new root development. And when this happens you know that the transplant was successful.
The best way to convert water roots to soil roots is to add a solid substrate, such as sand or fine gravel, that does not absorb water and does not float to the water pots and slowly decrease the water level either by scooping out a small amount every day and let the water evaporate naturally.
Converting soil roots to water roots is a bit more complex. It involves pruning back the plant and changing the water regularly. This type of root conversion should be done during the plant’s growing season so that it can be better able to withstand the stress of moving into a new environment.
But not all plants are suited for life in water and any attempt to convert these plants would fail.
Even for those that can adapt, it would be less traumatic for the cuttings and easier to propagate most plants directly in an aerated solid substrate, such as a mix of perlite/vermiculite mix.
You can read about whether it is better to root in water or soil for most houseplants here, the reasons why or why not.
Texas A & M University. (n.d.). Propagating Foliage & Flowering Plants – Ornamental Production Ornamental Production. Texas A&M.
Takahashi, H., Colmer, T., & Yamauchi, T. (2014). Aerenchyma Formation In Plants. Research Gate.
University of Nottingham. (2018). Divining roots: Revealing how plants branch out to access water. ScienceDaily.
Soil, S. A. (2021, May 21). How To Convert Your Roots From Soil To Water. Soak And Soil.
Reed, P. H. (2020, November 17). How to Convert Water Roots to Soil Roots in Propagating. Home Guides | SF Gate.
M. (2021, May 9). When To Move Monstera From Water To Soil. Better Leaves.