Edible Gardening

When is too soon to plant tomatoes? It’s a hot debate in Sacramento area

When to plant tomatoes? For best results and less work, wait until the ground is warmer.
When to plant tomatoes? For best results and less work, wait until the ground is warmer. Sacramento Bee Staff Photo

Is it too early to plant tomatoes?

That’s the top question on the minds of many Sacramento gardeners.

“We try not to burst out laughing when we get that question in February!” said Don Shor of Redwood Barn Nursery in Davis.

But a warm winter can warp perception. Spring-like weather prompted some local gardeners to dig in and transplant tomatoes weeks before what would be considered “normal.” Traditionally, tomato seedlings go in the ground in late April.

“In our area, the first nice weather of February brings out croaking frogs, mating skunks and gardeners at nurseries, looking for warm season vegetables and annuals,” said Sacramento radio host Farmer Fred Hoffman, a lifetime master gardener who now lives in Folsom. “Nursery people tell me, that because of climate change, many of those gardeners hunting for tomato plants are now requesting these tender young babies as early as January!”

This week’s frost was a reality check. Just when it felt like we were heading into reliably warm days, temperatures plunged down into the 20s – the coldest nights all winter.

Which meant that many newly planted tomatoes were toast, unable to withstand frost damage.

Said Shor, “We have laminated and posted signs (in his nursery) that say: ‘When do we plant tomatoes? When night temperatures are above 50 (degrees) F. or soil temperature is at least 60 F. By the calendar, that is usually late April. ... So, for best results, we plant tomatoes in April.”

Peppers and eggplants need even more warmth, he added. Those summer staples should be planted in May.

While some nurseries and big box stores already stock tomato seedlings, Shor waits to sell transplants.

“We bring them in mid-March but really don’t go full bore until early April,” he said. “I think it’s a disservice to gardeners to sell them plants that are just going to languish in the ground, waiting for warmer soil.”

Hoffman waits to plant his tomatoes until April 28, which he dubs Sacramento Tomato Planting Day. (It’s also his birthday.)

“There are several good reasons not to plant tomatoes around here in February: Day length (too short), nighttime temperatures (too cold) and soil temperatures (too cold, currently in the low 50s),” Hoffman said. “To actively grow, tomatoes need long, sunny, warm days; nights above 50 degrees; and, soil temperatures at least in the upper 60s. Generally, waiting until late April to plant solves all three of those criteria.”

Angela Pratt of The Plant Foundry in Sacramento’s Oak Park neighborhood understands both sides of the when to plant debate.

“We want customers to feel free to plant whenever the urge strikes and supply is there,” she said, “but we’ll want to have a conversation with them about soil and air temperature and growing conditions so they understand the downside to planting early. The upside, if you know what you’re doing, is an earlier harvest. There’s a bit of a competitive streak with tomatoes. If you can harvest early, that’s definitely something to brag about.”

Some hardy Sacramento gardeners don’t let chilly nights get in the way of planting their favorite tomatoes.

“Some nurseries already are selling tomato plants,” said Roseville’s Noe Fierros in early February. “It’s time to get them in the ground.”

Fierros is a tried-and-true tomato early bird.

“I usually plant them in late January or early February,” he said. “I purchase them as soon as I see them in nurseries.”

The more time in soil, the longer roots have to grow. And developing a big, robust root system is key to strong, healthy, productive plants.

Peter Frichette, Sacramento’s home-grown tomato king, always tries to get his plants off to an early start. The sooner in the ground, the earlier he’ll have his first Early Girl.

“I like to be the ‘first guy on the block’ with a ripe tomato,” Frichette said. “In some years, if we get a really warm February, I like to have a few transplants in the ground during the last few days of that month. You are much safer planting in late March or early April.”

Early transplants demand protection – just in case overnight lows plummet or chilly winds gust.

“If you do plant them now, don’t forget to cover the tomato cages with a clear plastic bag (such as a dry cleaners’ bag) that can reach the ground,” Fierros said. “The plastic bag creates a greenhouse effect, giving the tomato plant a longer, in-the-dirt growing season.”

Fierros used that method in 2017 and had fruit on all his vines before Memorial Day.

Gardeners, particularly in colder parts of the country, have developed many strategies to combat chill and get their tomatoes off to an early start. Some cover each plant with a plastic milk jug with the bottom cut out. Others use commercial crop covers or “Hot Kaps.” Others use plastic tubes filled with water, creating a protective wall around the tender seedlings.

“For those die-hards, we can chat about walls-o-water and Hot Kaps and other paraphernalia they can use to be the first on the block with a red, ripe tomato,” said Shor, noting that some varieties seem to get started with less heat.

“Good early varieties include Fourth of July and Early Girl, plus any small-fruited types like Sungold or Juliet,” he said.

Big Beef, a 1994 All-America Selection winner, has a reputation for producing fruit in colder temperatures, he added. Planted in early April, it will produce red ripe slicers by July Fourth.

“My tomatoes were just barely starting to set at that point,” Shor said. “So, I’m definitely trying that one this year.”

Added Pratt, “We think it’s more fun to tackle the temperature problem using the tools available to us and to get those tomatoes planted on the earlier side. Planting too late can be a very disappointing growing experience as well.”

Protecting tender tomato plants brings out gardener creativity.

“I do have a unique method of protecting the transplant,” Frichette said. “I use a 5-gallon plastic bucket which I have cut off the bottom 5 to 6 inches. I place this truncated top over the plant, then stretch a clear grocery plastic bag tightly over the bucket. They fit perfectly. I make a very small hole in the plastic, so as to let it breath a bit. It still swerves to keep some warmth in and protects the wee fellas from wind gusts. Those bags are not as plentiful as they once were, but they still may be found.”

Generally, February is for tomato seed starting, not transplanting. The seedlings grow quickly under lights or in a sunny window.

This winter, Frichette started his seeds in Jiffy peat disks or pods and saw the first sprouts within four days. Two weeks later, his seedlings stood 5 inches tall and were ready to move up to 4-inch pots. Seeds he started Feb. 4 will be ready to transplant in late March. He usually gives his tomato seedlings eight weeks from seed start to transplanting outdoors.

“This year, I am starting all of my plants from seed,” Frichette said. “A vegetable needs to continue to grow and never be slowed in order to attain its most potential. So this year, none of mine will have sat around some store in a little 4-inch pot and slowed down while waiting to be selected.”

It’s the ground – not air – temperature that can slow or speed tomato transplant growth. If the soil is still too cold, tomato plants just sit there and do nothing until temperatures warm.

Ideally, tomatoes like soil at 60 degrees F. or warmer. How can you tell if the soil is warm enough? Try sitting on the bare ground in thin shorts. If you can’t stay seated comfortably for more than a few minutes, the ground is still too cold.

Cool temperatures not only slow growth, they interrupt tomato blossoming and fruit set. Even if days are warm, tomato plants will drop their blossoms if overnight lows dip to 55 degrees – or lower. (Historically, Sacramento’s average night time temperature for February: 42 degrees.)

Because soil at night tends to be a little warmer than air, wait until overnight temperatures are consistently above 50 degrees before transplanting tomatoes without plant covers.

“A gardener can certainly shop for tomato plants when they hit the stores,” Hoffman said. “But baby them indoors, with bright light, during March. Starting April 1, begin acclimating them in their pots to the outdoors, in a shady location, gradually; a few hours a day, preferably during the warmest part of the day. Remember to keep them well-watered during that time; those small pots will be getting jammed with new, thirsty roots, so the soil will dry out quicker than when the plants were indoors.”

Still want to get those tomatoes started? Instead of transplanting directly into the ground, transfer young tomato plants to 1- or 5-gallon black plastic pots, which absorb heat and stay warmer overnight. Inside that heat wrap, the plants will form strong root systems with less stress. When transplanted into the garden in April, they’ll really take off.

“There’s always an element of mystery when it comes to growing tomatoes,” Pratt said, “so just have fun with it, and keep an eye on the weather, and be prepared to protect your plants if needed.”

Debbie Arrington: 916-321-1075, @debarrington

Best varieties for early tomatoes

If you’re determined to plant tomatoes in March (with hopes of ripe tomatoes by Fourth of July), try these varieties, developed for colder climates and recommended by Sacramento radio host Farmer Fred Hoffman:

Bush Early Girl VFFNT Hybrid: A bushy plant that produces 6- to 7-ounce fruit; determinate, harvestable tomatoes within 54 days after planting.

Clear Pink Early: This 2- to 3-foot-tall plant produces pink tomatoes, about 3 to 6 ounces each; determinate, 58 days.

Oregon Spring V: Developed at Oregon State University for short season gardens, this medium-sized fruit is nearly seedless; determinate, 58 days.

Prairie Fire: This bush tomato produces 3- to 5-ounce tangy tomatoes on short plants; determinate, 55 days.

Siberia: A favorite of Canadian greenhouses, this bushy plant reportedly will set fruit at temperatures as low as 38 degrees. Fruit is under 2 inches in diameter; determinate, 55 days.

Siletz: A 10- to 12-ounce tomato developed in Oregon; determinate, 52 days.

Tumbler: Producing cherry-sized tomatoes in seven weeks, it’s a good choice for hanging baskets; determinate, 49 days.