Tender Annuals: Is it time yet? — by Julia Frisbie

by Julia Frisbie

posted May 10, 2022

I’ve only been growing here for six seasons, but still, I can’t remember ever waiting so long to transplant my tender annuals. I’m on a tight schedule this spring, and getting very antsy. But the dang weather forecast is still showing temps in the 40s and 50s for the next week! What to do? To guide my plantings, I’m considering recent garden records, phenological cues, historic temperature data, and the way the soil feels.

RECENT GARDEN RECORDS

Having access to this information is one great reason to keep a garden journal. As I read through old entries, I found myself wishing that I’d recorded soil temps along with dates, so I’ll do that from now on. These are the notes I’ve taken about transplanting my heat-loving annuals over the past 6 years, along with some information that Peter Heffelfinger has shared right here on the Fidalgo Grows blog. Note: both of us grow with Southern exposure in raised mounds that allow our soil to dry out reasonably early, my garden has good wind protection, and he has a small hoop house.

• 2016: I planted heat-lovers in mid April. (We’d just moved, and didn’t have any proper garden beds yet, so I did most of my tender annuals in straw bales that year. They heat up faster than the ground.)

• 2017: The soil was 55 degrees by April 11. It felt like I started heat-loving seed both too early (April 25) and too late (May 10), so we purchased starts from Christianson’s and planted them around Mother’s Day. But… we still didn’t get many tomatoes. I had a new baby that year, and my garden journal sadly admits: “Anything that needed special attention suffered.”
• 2018: I planted tomatoes and cucumbers into holes in plastic mulch on April 28 and May 5. I covered them with a remay frost blanket when I first transplanted them, and took the remay off on May 11. This led to my first tomato ripening on July 7, and great harvests into late summer and fall.
• 2019: we got a week of gentle rain and mild temps, so in a fit of enthusiasm, I started transplanting tender annuals into raised mounds of soil warmed by plastic mulch during the first week of April. I finished planting dahlias by April 27, the first red poppy bloomed on May 8, and of course we finished the drip irrigation system over Mother’s Day weekend.
  

• 2020: I planted out my dahlias and heat-loving veggies from May 1-6 (most were transplanted, beans and corn were direct sown). Peter wrote that early May was the time to transplant tomatoes, once the soil is warm and nighttime temperatures are above 50 degrees.
• 2021: I planted dahlias (and got my inaugural sunburn of the year) on April 14 because the lilacs were already budding and I could comfortably walk barefoot on the soil. The first heat-lovers got transplanted into plastic mulch on April 18, dahlias had emerged by the 27th, and I transplanted the last cucumbers on May 19th. Peter bought his tomato starts and began hardening them off around April 27.

PHENOLOGICAL CUES

My neighbor’s lilacs are now in full rolling bloom. I learned from one of the long-time growers of the Whatcom County Dahlia Society that when the lilacs are budding, it’s safe to plant dahlias in raised beds or mounds, so that was my go-ahead; I finished planting my dahlias last week.

In 1996, the Ahkwesahsne Mohawk Board of Education instructed my seed-saving mentor Rowen White that, “When the leaves of the dogwood are the size of a squirrel’s ear, it’s time to plant corn.” I don’t have any native dogwoods, so I keep track of the blossoms on an ornamental dogwood who has been in this spot longer than we have and knows it better than we do. Blossom development seems right on schedule:

My mentor Rowen suggests another cue to watch for: wild blackberry buds. She says that when they’re swollen and just barely starting to open, it’s time to plant. I encourage you to find the wild blackberries closest to your garden that share a similar orientation (north, south, east, or west) and check on them. Here are the south-facing wild blackberry buds closest to me:

They don’t look like they’re going to open up this week.

HISTORIC VS. CURRENT WEATHER

If you toggle the right settings, the website weatherspark.com will allow you to see current temperature data superimposed over historic averages. Here’s a look at April and May 2022:

Look how much the gray marks are hanging out in the blue rather than the red, and how the trend of the gray marks doesn’t match the upward slope of the average historical trends yet. Compared to past years, this has been a cool spring.

THE WAY THE SOIL FEELS

If you’re a regular reader, you know that I enjoy gardening barefoot. This gives me a lot of sensory information that I wouldn’t have otherwise. But if you want to keep your shoes on, you could get similar information by…

• Kneeling. How wet do the knees of your pants get?
• Pulling weeds without gloves on so that your hands are in it.
• Using a soil thermometer. (Just remember that the results may vary from bed to bed; measure them all!)

At this point, some areas in my garden have reasonably dry, warm soil… and some parts are still cold mud.

The bottom line is: the calendar says it’s time. Phenological cues say maybe. Historic vs. current weather patterns say maybe not. At this point, it all depends on your planting area. Is it raised? Sheltered from wind? Covered in plastic? If so, go for it! If not, better keep touching the soil regularly. There is simply no substitute for sensory input.

Let me know in the comments what your soil feels like and what you’ve planted so far!