Stale Morning Coffee: Your Tomato Plant Will LOVE You For It!

Every single morning, I wake up and stumble into the dark kitchen to get my morning coffee going.

Even though I have automatic settings at my disposal, I still slowly stomp along, and prepare my fairly basic coffee maker in a zombie-like state as if those magical settings didn’t exist.

I then enjoy the ever-loving mess out of that delicious hot bean juice, and toss my spent grounds into the compost bucket.

If you over brew like I do, you probably just toss that old, stale coffee down the drain with a bit of a frown right around noon time.

I’ll be honest, for a long time, I felt bad about wasting the excess coffee, even if it was just an ounce or two. I like to upcycle things and get the most life that I can out of them, especially food waste and plastic waste.

I then had this epiphany: if the compost loves coffee grounds, well, what about the brewed coffee? Surely I can use that old coffee when I brew too much of it…

Today, I want to tell you just how much your tomato plants are going to love you for your stale coffee- the stuff that’s been sitting cold in your coffee pot for the past three hours.

How to Water Tomato Plants with Coffee

When you’ve finished your morning coffee, grab a jug or a bucket and pour the cooled remaining coffee into it.

Dilute the coffee with water, with the coffee making up no more than 25% of the solution. If you have a large garden and have excess daily, you could dilute it much further for more frequent use- down to 5%.

Water your plants with your weakened, watered down coffee lightly, taking care to water 4″ away from the plant. This helps to prevent concentration of the coffee fertilizer at the roots of the plant, which reduces the effects of acid buildup.

It’s a great natural fertilizer to use alongside others, such as banana peel fertilizer (which is rich in potassium and phosphorous!) and egg shells (they’re great for calcium!)

Avoid watering a plant with 25% strength diluted coffee more than once per week; if the solution is weakened to half that or less, a plant could be watered with it more frequently.

Do not saturate the ground as you would when watering with a hose; a quick pour will do!

What Does Leftover Coffee Do for Tomato Plants?

Coffee is high in nitrogen, but is also slightly acidic.

The nitrogen is perfect for supporting the growth of lush foliage, which is vital for producing your biggest, juiciest tomatoes– however, you don’t want the tomato plant to receive too much nitrogen, as that may hinder fruit production.

The same is true about the acidic nature of coffee. Tomatoes enjoy slightly acidic soil, so this is an opportunity for those with alkaline soils to increase acidity. However, too much coffee too often could pose an issue with soil becoming too acidic.

What Other Plants Enjoy Leftover, Stale Coffee?

If you only have a few tomato plants, there are other garden plants that would love to get their roots on old coffee!

If you have any of the plants listed below, try giving them a dose of your morning java.

  • Blueberries
  • Azaleas
  • Rhododendrons
  • Dogwoods
  • Magnolias
  • Hydrangeas
  • Daffodils
  • Marigolds
  • Iris
  • Gardenias
  • Begonias
  • Elderberries