How to grow flowers throughout the summer

Written By brooke bonzo

Did you now you can still plant flowers through June? Well, its true!

In this blog I’ll teach you how to look at a packet of seeds and know whether or not you can still plant them this year. I’ll also list some of my favorite heat loving annuals that I plant through June, that you can plant this week too!

First things first

Here are 3 things we will go over:

  • Days to maturity for any given variety

  • Your last and first frost date and how to use them for mid-season planting

  • How to determine the best growing conditions for different varieties

Days to Maturity

Days to maturity refers to the number of days that plant will take to go from planting to flowering. This info is typically printed somewhere on the packet of seeds, if not google is your BFF in this situation. For example, Procut Sunflowers are listed as 50-60 days to maturity. I know that when I plant that sunflower seed I can expect it too bloom in roughly 50-60 days. Of course weather and soil play a part in that time as well but assuming you have sun, heat and water you can reasonably rely on that number. Knowing a plants days to maturity is crucial when you have a shorter growing season like we do here in parts of Michigan!

How to plant seeds, What to plant in June, Seed Packet, Planting

Here is an example from 2 different companies. On the left is a packet of Johnny’s Selected Seeds where you can see the days to maturity is simply written as “Days” on the front of the packet of these Gomphrena. On the right is a packet of Floret seeds and its listed as “Days to Maturity” on the back of the packet for these Chinese Forget-me-nots.

Frost Dates

Your first frost date is the date each fall that your area, on average, will have its first 32 degree or less day which is a killing frost for most annual flowers. Your last frost day is the date each spring that, on average, you can expect to be your last day that dips to 32 degrees or less.

Knowing these two dates allows you to know how many days you have for growing fruits, veggies or flowers. Here in Rockford our average last frost date is May 15th and our first frost date on average is October 5th, that gives us about 144 days for our growing season. Now that I know I have 144 days to grow I can easily look at a plants days to maturity and know if that variety can be grown during our growing season.

If your season has already started simply calculate how many days are left between now and your first frost date to know if you have enough time left. For example, there are 110 days between today and Oct. 5th and the Zinnias I want to plant take 75-85 days to mature. I can absolutely plant them today and know I will have several weeks to enjoy them!

Could you start plants early inside to get a head start and ensure that any plant that takes a long time to mature will bloom before first frost? Absolutely! But that’s a post for another day :)

Ideal Growing Conditions

Now that you know how to determine if you have enough time to grow a certain flower, you need to consider what growing conditions it prefers. There are 2 different types of annuals;

Hardy Annuals and Tender Annuals (also known as heat loving annuals)

Hardy annuals prefer cool weather while tender annuals like it hot.

Hardy annuals include:

  • Snapdragons

  • Bachelors buttons

  • Larkspur

  • Nigella

  • Poppies

  • Bells of Ireland

  • Corncockle

.…Just to name a few! These are the first flowers to bloom in the Spring and can handle freezing temps, frost, snow and generally any conditions I don’t want to be out planting in 😂 These guys need to be planted early (or even the fall before) to thrive. Once the summer heat starts to amp up they will fade or stop flowering all together. These are not good options for planting in June. — Queue the heat-loving annuals!

Heat-loving Annuals include:

  • Zinnias

  • Sunflowers

  • Celosia

  • Cosmos

  • Strawflower

  • Gomphrena

  • Basil

Heat-loving annuals thrive in the dog days of summer so these are the ones you wanna plant in June! The long, hot days speed up germination and growth giving you plenty of time!

Lets look at a few examples:

  • Let's take Zinnias -They have a days to maturity of around 75-85 days and they are a tender annual. If we work backwards and count 85 days from our first frost date of October 5th, we get July 12th. In Theory you could plant Zinnias as late as mid-July and still get blooming flowers if you don’t get a frost before October 5th. Now, do flowers ever follow exactly what we want them to do? Absolutely not. However, it's very reasonable to plant Zinnias straight into the ground throughout June and still get to enjoy them before your first frost, even if it comes early that year!

  • Now lets look at Bachelors Buttons - They typically take around 65 days to mature. Very doable here in Michigan. However, when you read about what environment they grow best in you’ll see that they are a hardy annual. They do best in cool weather, with high heat causing short stems and poor germination. Could you still plant them in June? Sure. Will they grow? Maybe, but more than likely they wont germinate and you’ll end up disappointed. Save these seeds for next spring!

Here are 3 flowers I’m planting this June:

  • Zinnias - They come in LOADS of colors and shapes. Have you seen cactus zinnias??

  • Sunflowers - This is a fan favorite. My favorites are the Procut varieties. The Procut’s produce one, strong stem and are pollenless so no messy countertops!

  • Cosmos - These delicate looking flowers are workhorses. They can fill a space in no time and come in a lot of cool varieties like cupcake, orange, pink, white and more!

So while you do need to be careful about what you plant in June, because lets be honest, there’s nothing more disappointing or discouraging than planting a row of seeds, eagerly waiting for them to emerge and getting nothing…ask me how I know 😔…there are still plenty of varieties you can choose from!

Happy planting fellow flower loving folk!
- Brooke

brooke bonzo