The Tomato of My Eye

sarahjGuest post: Sarah Johnson is a Northside Community Garden Mentor, and also an expert on tomatoes.  When she agreed to do a blog post for us on tomatoes, and we were tickled pink (or should I say red?).  If you want more info, Sarah will also be leading a workshop geared for community gardeners on July 14th, 5:30 – 7 pm at the Northside Community Garden.  Give Garden City Harvest a call 406.550.3663 if you’d like to join in the fun (it’s free).
My tomato education began five years ago on a cold June afternoon.  I was working on Killarney Farm that summer,  nestled in North Idaho surrounded by nothing but national forest.  Farmers Paul & Ellen of Killarney Farm grow over 30 different tomato varieties.

On the afternoon of my arrival, I stood in a warm moist greenhouse seeking respite from the rain, breathing in the scent of hundreds of potted tomatoes bound for market.   Over the next five years I worked closely with farmer Ellen learning how to tend, care for, and appreciate the unique attributes of the many tomato varieties.


One of my favorite parts of the job was helping customers choose their tomatoes at the Kootenai County Farmer’s Market. The chance to educate customers on features and planting techniques was key to their success at home. Here are some of the questions I learned to ask our customers as the decided what to plant.

Top 5 questions to ask yourself when choosing a tomato for planting:

  • What am I gonna use it for? (proper North Idaho back woods English)
  • Do I want small, medium, or large fruit size?
  • Heirloom? What does heirloom mean anyway?
  • Determinate or Indeterminate?

heirloom tomatoesWhatcha gonna use it for?

There are so many ways to use tomatoes: salads, salsa, sauce, sandwiches, snacks… it makes your head spin. These questions will help narrow down the variety of tomato that will be right for you. For example, if you plan on making sauce till the cows come home then a nice meaty paste tomato will serve you much better than a juicy salad tomato.

Fruit size

  • a small cherry tomato is 2 to 5 oz or the size of a large gumball
  • a medium tomato is 6 to 10 oz or approximately the size of a tennis ball
  • a large tomato is 10 oz+ and can be the size of a softball

Heirloom – what does it mean?

An Heirloom is open-pollinated (by birds, insects, wind) and has been cultivated for at least 50 years. An heirloom must be open-pollinated, but not all open-pollinated plants are heirlooms.

This is in contrast to a hybrid where different varieties are cross-pollinated by human intervention. Hybridization may also occur naturally but when buying plants the seed is usually denoted by ‘F1’. Heirloom does not always mean a better tomato. Choose a tomato that fits your taste!

Determinate vs. Indeterminate

A determinate tomato grows to one size (also called bush tomatoes), sets its fruit over a couple of weeks, ripens, and is done for the season. These tomatoes may be caged for support. An indeterminate tomato, or vine-type tomato, continues to grow and shoot new flowering tops, getting infinitely taller and producing fruit over a longer period of time. An indeterminate tomato needs pruning and a greater support structure during the growing season.

Transplanting tips

Growing space: Cherry tomatoes and compact determinate tomatoes work well in containers 18”-24” in diameter. Tomatoes planted in the ground should be 24”-36” for the best production.

Choose a sunny location that receives 6 hours or more of direct sunlight each day.

Prepare the soil:

Dig a hole large enough so that you may transplant the tomato up to its second set         of leaves. A trench may also be dug and the plant can be laid into the soil at a slant with only its head sticking out of the ground. Throw a handful of compost or composted manure into the hole & mix well with soil. At this point you may add an organic tomato/vegetable fertilizer to the soil or water your transplants in with an organic liquid fertilizer such as fish emulsion.

Prepare the tomato for transplant:

Pinch the bottom leaves off the stem of the tomato plant. Gently pull the tomato out of    its container and massage outer roots slightly to loosen the root ball without damaging the root system. Place tomato into hole or trench so that the entire stem will be buried up to its leaves. The tomatoes will form roots from the stem that is planted underground forming a more solid root structure for the plant. (Tomatoes are super cool plants!)

Watering Tomatoes:

Water transplants in thoroughly. After initial watering, water regularly but let the soil dry out between watering, as over-watering can lead to disease in plants. Give the plants an inch* of water every week, two inches when the weather gets really hot (that equates to soaking the plants thoroughly every 4-5 days for well-drained sandy soil and every 7-10 days for heavy soil).

*There are many ways to measure ‘an inch’ of water. The easiest way is to set a container out under your sprinkler, drip line, etc & water until you have 1 inch of water in the container.


Make sure your tomatoes are hardened off (aka being introduced slowly to being outside over a week or two). Tomatoes may be transplanted after the last frost date (May 19th in Missoula!) and when the night time temperatures are consistently above 55 degrees Fahrenheit.  If you have already planted your tomatoes, don’t fret! Tomatoes can be covered with an old sheet or fancy row covers at night to ensure that they stay warm. Tomatoes can tolerate temperatures below 55 degrees F but start to show cold damage if the temperature drops to 40 degrees F.

Want to learn more?  I am hosting a workshop for community gardeners on tomatoes.  Join me Tuesday, July 14th from 5:30 – 7 pm at the Northside Community Garden.

Happy Growing! I wish you a plateful of Tomatoes later this season!