Homegrown Tomatoes

Posts Tagged ‘fertilizer’

Tomato fertilizer isn’t just any old thing you see on the shelves of your local garden center.  What’s right for other veggies and plants might not be what you want for growing tomatoes.  So here’s a quick discussion on the components of fertilizer (what those numbers mean) and how they relate to tomatoes.

Fertilizer Components

Your average plant fertilizer is primarily made up of three components:  nitrogen, phosphorus and potassium (N-P-K).  While there can be various micronutrients present, the numbers (like 8-3-2) you see on the fertilizer refer to the relative amounts of nitrogen, phosphorus and potassium (in that order).  And that’s what this post will discuss.

Nitrogen

Nitrogen is the first number indicating the fertilizer strength, and nitrogen is primarily responsible for foliage — making it strong and healthy.  And while the tomato is first growing, that’s exactly what we want — a good strong plant.   When just setting out plants into the garden, something along the lines of 10-5-5 is nice — you want the foliage to be plentiful and strong.

Phosphorus

Phosphorus is of interest to tomato growers because it’s a necessary nutrient for plenty of blossoms.  Without blossoms, you won’t get tomatoes!  After the tomato plant has adjusted to being out in the garden and has plenty of new growth, it’s time to increase the ratio of phosphorus.  Now you want more phosphorus than nitrogen (example, 5-10-10).

Potassium

Potassium is used for regulating the water content of a plant; its transpiration.  If there isn’t enough potassium available, the plant is more vulnerable to droughts, be they temporary (forgetting to water one day) or longer-lasting.  Once the plants are established, something along the lines of 5-10-10 are good.

The Strength of the Numbers

Don’t go thinking the higher the numbers the better — if 5-10-10 is good, then 10-20-20 is great.  Not so, as fertilizer that is too strong can burn the roots as they try to develop.  I prefer to use a weaker fertilizer with the same relative percentages, and even then, I don’t always use it at full strength.  Instead, I prefer to fertilize a little more often; this seems to give me a good balance between feedings and how much the plant can use at a time.

As you’ve probably gathered in my other posts, I prefer to use organic fertilizer wherever possible.  In additional to Terracycle and sea kelp, one fertilizer I like to add in is a fish emulsion. Since I can’t seem to find it locally, I get it online and I find that my plants really like it.  It’s concentrated, so just a little bit mixed in with some water goes a long way.

It’s time to learn about tomato growth requirements — what they like, in order to grow best.  While individual varieties may be better for warmer or cooler climates than you average tomato, you still need to know the basics.

With that thought in mind, here are the basic requirements for growing tomatoes.

Tomato Growth Requirements

Like most fruits and vegetables, tomatoes require at least 6 hours or direct sunlight a day.  Tomatoes also require warm weather — frost will kill them.  The ideal temperatures for most (not all!) tomatoes is the upper 70’s to low 80’s during the day, with nights in the 60’s. (Temperatures in degrees Farenheit.)

However, tomatoes will grow and set fruit in warmer weather, as well as in cooler weather; they just won’t be quite as productive.  Keep your local temperatures in mind when selecting tomato varieties.

For example, a grower in the cool Pacific Northwest would be better off with early tomatoes (those that mature in 67 days or less), as well as tomatoes that are bred for cooler weather.  On the other hand, someone in the desert Southwest would be well-advised to select tomatoes that have a good track record of bearing fruit in hot weather.

So, keep your local climate in mind when selecting tomato varieties. Oh, and an adequate water supply is essential for tomatoes to produce fruits; an average of an inch of water per week is considered optimal, but if you live in a dry climate, you might want to provide a bit more; tomatoes can get thirsty!

And if you live in a hot and humid climate (like me) — be especially careful with your fertilizing schedule, and know the tomato diseases that thrive in a hot, humid environment.