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Potting media for plants: testing ProMix soilless mixes

A begonia plant potted in ProMix
A begonia plant potted in ProMix
Photo by Jane Gates

ProMix potting media for gardening


When it comes to potting up plants large and small, there are different choices for media. There are potting soils, composts, and soilless media and more to choose from. Most of the soilless mixtures are based on sphagnum peat moss. The advantage to using these potting mixtures is they are free from the harmful pests or diseases that can hitchhike in on packaged soils. They are also less likely to stain surfaces below the pot.

Recently I’ve had the opportunity to try out a line of soilless potting mixtures made by a Canadian company called ProMix. It is considered a non-soil potting material with mycorrhizae to aid with transplant stress. The company offers a whole line of different blends – for cactus and succulent plants, African Violets (and other related humus-loving tropical plants), seed-starting, vegetables -- all offering slightly different recipes to provide the right moisture retention and aeration that will help plants become well-rooted and thrive.

Now that I’ve used the ProMix seed mixture, there is no way I’d consider returning to regular soils for germinating my seeds. Most commercial soils don’t have the fine texture I like for small seeds and to retain water reliably. The soilless mixture does not sprout weeds, mushrooms or carry the diseases I've found with other products. It was easy to use and my seedlings liked it as much as I did.

The house plants I potted with ProMix medium have not only avoided the check in growth common to transplant shock, but have put out healthy new growth in less than two weeks after re-potting. Plants do need regular feeding since soilless mixes offer a sterile medium only.

I prefer sharp sand in my cacti and succulents potting medium and did not find it in the ProMix formula offered for these plants. So I added the sand and everything is growing just fine. The medium drains fast so I don’t worry about over-watering.

The vegetable mix is home for the roots of my precious potted grafted vegetables. So far it is living up to the demands nicely. I feed them with fish emulsion and moo-poo tea (manure tea) and the plants are thriving. They are set on a cement foundation so I like the fact this medium doesn’t stain the area like most others will do when water drains through the bottom of the pot.

On the whole I don’t see a radical difference between the ingredients and the look of the different mixtures put out by this company. Still, I am very pleased with the fine texture and water retention/drainage of the products overall. So far I have been working with the ProMix line of potting media for about six months. It has delivered enthusiastically growing house plants, thriving succulents and happily sprouted seedlings. I will look for ProMix now that I have used up most of my stash. I’ve used many potting mixes and soils and not been all that impressed with the majority I’ve bought from home stores and garden centers.

You can find the ProMix products offered for sale in the big box stores, garden centers and many other retailers across the country. Priced competitively, I have been convinced to opt for soilless rather than organic soils for my potting needs. This brand is easy to find on the Internet, too.