Spring heat wave may lead to early tomatoes

Happy first day of spring! Did you remember your sun screen?

This new season starts where winter left off – with record warmth. According to the National Weather Service, most of the greater Sacramento area will continue to set new record highs along with some record warm lows.

Before this week, the all-time hottest March day in Sacramento registered 88 degrees. Average historical highs for this week: 65. Meanwhile, we keep flirting with 90 degrees – 25 degrees above normal for our first day of spring.

Overnight lows are unusually warm, too. Instead of dipping down to the mid 40s, nighttime temperatures are staying in the 60s – leading to warm mornings. Normal lows for this date: 44 degrees.

All this warmth has led to a rapid speed-up of spring activity. A lot of late winter/early spring flowers – including daffodils, tulips and camellias – are already spent. Fruit trees are dropping their early flowers almost as soon as they open.

Did bees have an opportunity to pollinate those quickly fading blooms? We’ll find out soon.

According to the weather service, these temperatures look more like May or even June than mid March. Soil is warming dramatically, too. Which may mean it’s already time to plant tomatoes.

Generally, tomatoes need soil to warm up into the 60s and 70s before planting for good root development. (When transplanted into cold soil, they just sit there and don’t grow.) In normal years, Sacramento doesn’t see those soil temperatures until mid to late April.

But this spring is different. Soil temperatures are soaring.

According to Syngenta’s GreenCast online soil maps, California is (comparatively) red-hot. Sacramento’s average soil temperature jumped from 45 degrees on Feb. 20 to 72 degrees on March 20. Our normal soil temperature for this date: 58.5.

This continued heat wave (including those warm nights) is speeding up spring growth literally from the ground up.

In addition to moving up planting dates, this heat taxes soil moisture – and our irrigation. Make sure your plants get the water they need while they’re growing their fastest.

March was not only hot, it’s been dry. Sacramento has not recorded any precipitation this month, says the weather service; Sacramento’s average rainfall for these first three weeks, 1.8 inches. Deep-water plants and apply fresh mulch.

Before planting all your summer veggies, remember: April weather can be unpredictable. It’s warm now, says the weather service, but expect some cooler – and more spring-like temperatures – in the weeks to come.