Magnesium for Plants
Give plants targeted magnesium support when leaves show signs of magnesium-related interveinal yellowing. Magnesium plays an important role in chlorophyll and healthy green foliage, making this a focused supplement when additional magnesium is needed.
Use it alongside your normal feeding program as directed for controlled, consistent support.
Made by growers
More than a bottle on a shelf.
- Talk to real plant people. The team that mixes the formula answers your email.
- Made in-house, in the USA. Every bottle mixed and filled by us, not a third party.
- We're growers, not resellers. We use this on our own plants before it ships.
- Bundle savings only here. Pair any two TPS formulas — your order ships free.
Magnesium for Plants with 5% magnesium — a magnesium supplement, not an NPK fertilizer, made to correct the interveinal yellowing that a magnesium shortfall causes. Magnesium sits at the center of the chlorophyll molecule, so when a plant runs short, its older leaves yellow between the veins while the veins stay green — and this delivers magnesium directly to green them back up on new growth.
How to Use Magnesium for Plants
| Method | Amount | How Often |
|---|---|---|
| Watering can | 1-2 tsp per gallon of water | Spring & Summer: apply once weekly |
| Watering can | Same dilution | Fall & Winter: every 4-8 weeks |
| Hose-end sprayer | Set to 2 tsp setting | Spring & Summer: apply once weekly |
| Leaf misting (optional) | 1 tsp per quart (32 oz) of water, spray on leaves | apply weekly |
Use as a magnesium supplement alongside your regular fertilizer, not in place of it — this supplies magnesium, not N-P-K.
What's Inside
This is a magnesium supplement rather than an NPK fertilizer, so there's no nitrogen-phosphorus-potassium ratio — it targets one nutrient. The 5% magnesium comes from magnesium sulfate, and magnesium is the atom at the center of every chlorophyll molecule, which is what makes it essential for photosynthesis and green color. Because magnesium moves within the plant from old growth to new, a deficiency shows first on the older, lower leaves: yellowing between the veins while the veins themselves stay green, sometimes with the leaf edges curling.
Beyond magnesium: sea kelp (Ascophyllum nodosum) for natural growth compounds that aid uptake. This is a deliberately focused magnesium supplement with no added nitrogen, phosphorus, potassium, or other micronutrients. Magnesium deficiency is common in sandy soils, acidic soils, and containers, and in heavy potassium situations where potassium competes with magnesium uptake. Use it to correct that specific interveinal yellowing, alongside a complete fertilizer that covers the plant's other needs.
Made For
Built as a magnesium supplement for plants showing interveinal yellowing on older leaves — tomatoes, peppers, roses, citrus, and palms — and for gardens on sandy or acidic soils or in containers where magnesium runs short, used alongside a complete fertilizer.
Problems It Solves
- Yellowing between the veins on older, lower leaves
- Green veins on otherwise yellowing older foliage
- Magnesium deficiency in sandy or acidic soils
- Pale, tired foliage on container plants
FAQs
How often should I use magnesium for plants?
In spring and summer, apply once weekly at 1-2 tsp per gallon, using a watering can or a hose-end sprayer on the 2 tsp setting. In fall and winter, cut back to every 4-8 weeks. Use it alongside your regular fertilizer, not instead of it, since it supplies magnesium rather than N-P-K. Treat when you see the telltale interveinal yellowing on older leaves, and continue while new growth greens up over the following weeks.
What are the signs my plant needs magnesium?
The classic sign is yellowing between the veins on older, lower leaves while the veins themselves stay green — sometimes with leaf edges curling or turning reddish. It appears on old growth first because the plant moves magnesium to its new leaves when short. If instead the yellowing is on new growth, that points to iron; if whole leaves yellow uniformly, that's nitrogen. Matching the pattern and leaf age to the right nutrient saves you treating the wrong thing.
Is this the same as Epsom salt?
It's closely related — the magnesium in this product comes from magnesium sulfate, which is what Epsom salt is. The advantages here are a consistent, measured concentration and the added kelp for uptake, formulated as a plant supplement with clear rates. So it does the same core job of supplying magnesium and sulfur, in a form made for straightforward garden use. Either way, it's a genuine magnesium source, useful specifically when a magnesium shortfall is the actual problem.
Why do container plants often need extra magnesium?
Containers lose magnesium quickly, because frequent watering leaches it out of the limited soil, and potting mixes often start low in it. Heavy feeding, especially with high-potassium fertilizers, makes it worse, since potassium competes with magnesium for uptake. That combination means potted plants — and plants in sandy or acidic soils that hold magnesium poorly — show magnesium deficiency more often than those in rich garden beds. A magnesium supplement corrects the gap those conditions create.
When will I see results?
New growth greens up over a couple of weeks once magnesium is available, and a foliar application can speed visible improvement. Existing yellowed leaves may partly recover but often won't fully re-green, since the damage is already done — so you're mainly feeding healthy new growth. For an ongoing tendency toward magnesium shortfall, like sandy soil or containers, steady use through the season keeps it from recurring.