What's happening in the mid-March garden

Daffodils and hyacinth blooming, daylilies sprouting

Sunday, March 15, 2026

Spring in our garden came 2-3 weeks later this year with unseasonably frigid temperatures in February.  Daffodils, hyacinths, forsythias and Bradford pear trees are in full bloom.  Redbuds are beginning to bloom,  lilacs and roses just leaved out.  Peonies are just breaking ground.  Apple trees buds are just swelling.

When forsythias bloom, it is time to apply corn gluten for weed suppression in the garden and yard.  Corn gluten keeps seeds from sprouting and provides nitrogen.  It will also keep grass seed or garden seed from sprouting so use only where you don't want seeds to come up.

In the edible garden, onions, tarragon, garlic chives, garlic, carrots and spearmint are all coming up in the garden bed and pots.  Overwintering arugula, celery, winter cress, strawberry plants, raspberry plants, blackberry bushes, thyme and oregano are growing again.  Chickweed is flowering and growing vigorously.  The garden is giving greens for fresh picked salads.

I have been sowing cold season crop seeds outdoors for a while now.  I started in February with snow peas, lettuce and spinach in pots in the portable greenhouse.  I haven't seen any come up.  The soil could have been too wet and the seed rotted.  I've started lettuce and spinach indoors and those are up. I'll transplant from peat pellets to small pots in the next week.  When this next cold spell gets through and the weather looks safe from the 20's, I'll start hardening them off outdoors and transplant them. 

I'm hoping lettuce and spinach transplants will be available at the big box stores this weekend.  I like getting a couple 6 packs to get a jump on spring salads.

Peas and potatoes can be planted as soon as the soil can be worked in the spring.  I planted potatoes a couple of weeks ago.  The ones with long shoots are turning green so far, so good on them.

I have started other lettuce indoors that are heat resistant like Lunix, Solar Flare, Bronze Beauty, Royal Oak Leaf, Red Sails, Yedikule and Butter King.  Also started other summer salad greens in my Aerogarden system: Chinese pink celery, Hilton cabbage, Barese Swiss Chard, Japanese Mountain Spinach (a Swiss Chard), Chijimisai Greens, a fewamaranths, and mixed colors orach.  They are sprouting and the lettuce is ready to transplant into bigger pots.

I only started rosemary, papalo, and bushy sweet basil in the Aerogarden.  Parsley and celery overwintered and I'm hoping for volunteers of dill, cardinal basil, blue spice basil, and purple ball basil.  So far, my garden sage survived the winter along with the gold and green variety.  None of the tricolor sage survived.  I hope they survive this next dip into the 20's!  That's the killer for plants that are susceptible once there has been a warm up and then another cold snap.  It gets my rosemary almost every time.

Early March is an ideal time to mulch.  It's before the self-seeders are sprouting and it adds warmth to soil. I'm still working on gathering the seed heads from the marigolds, zinnias, cardinal basil, cockscomb and Jerusalem artichokes before mulching.  With the frigid temps moving back in tonight, it may be the first of April before adding compost, fertilizer and mulch to the beds.

For growing edibles, you can count on needing at least nitrogen addition unless you are doing nitrogen fixing cover crops.  I have tried a few different all natural nitrogen fertilizers.  Kelp adds a variety of minerals plus it has growth hormones in it so is a great choice for plants you want a lot of height for.  Many of the organic fertilizers use chicken manure as a main component.  We have chickens so I compost their bedding to use in the garden.  I use alfalfa meal and blood meal which are good sources of nitrogen for planting and adding to my greens during the growing season.  For all purpose organic fertilizer I use Espoma Garden-Tone or Re-Vita.

If you are creating new beds, put down cardboard first before fertilizing and mulching.  This added layer will keep the grass and weeds smothered while attracting earthworms.  Earthworms love cardboard!  They not only loosen the soil, but also fertilize it.  A real win-win. 

If you don't have a lot of time this year, transplants are always a great option.  Cool season crop transplants are at the local nurseries and big box stores in the next week or two.  They'll have broccoli, cauliflower, cabbage, onion sets, lettuce, strawberries, potato sets, boxed dormant fruit bushes and trees in the first arrivals.  They sit outside so they are already hardened off and ready to plant.

Overwintering cabbage and broccoli

The big box stores will also have herb transplants.  The ones that can be planted now are thyme, sage, garlic, parsley, and celery.  I'd hold off on the rosemary and especially the basil.  If it gets even close to freezing, basil can be killed in the garden.  You can buy and keep them in a sunny window in the garage and they should be fine.

Tomatoes and basil will be in the stores, too.  I'd wait on those.  Tomatoes, basil, peppers and eggplant all need warm days and warm soil to thrive.  A freeze can kill them.  I usually wait until May to plant these summer lovers.

Indoor seed starting week 2

Hydroponic seed starting system
Saturday, March 14, 2026 

Now is the time to get the jump on summer harvests and start the warm weather loving seeds indoors.  Here is what I started indoors in my second week of seed starting.

Summer greens-these are the greens I use for salad after lettuce has bolted in the summer.  Aurora mixed colors orach, Rose orach, Double purple orach, Golden Giant amaranth (for leaves and seeds), Beetroot amaranth, Callelo amaranth, Rainbow quinoa (leaves and seeds).

Flowers-Orange King zinnia, Blush hollyhock, Purple stardust, Baby Blue Bouquet eucalyptus, Baby Blue Eyes, Rainbow Loveliness dianthus, Amadeo coneflower, Bluebird Forget-Me-Not, Scarlet echinacea, Platinum Blue, Blue Queen Butterfly Pea Vine, Blue Camas, Raspberry Daiquiri agastache, Sky Dance salvia, Kiwi Blue honeywort, variegated cockscomb, Red Raven cockscomb, Dwarf Coral cockscomb, Copper Spotted petunia.

The large flowers are for the pots in front, the smaller flowers for the pots with edibles, the dwarf cockscomb for around the flower bed perimeter and the perennials for the spots that either had annuals last year or the perennials didn't make it.  I'll also supplement the border with marigolds because they are so cheery, they deter deer, and pollinators love them.

I'll start the larger seeds outdoors at the beginning of April like cucumber, squash, okra, pole beans, melons and flowers.  I still also have seeds to start at our Master Gardener Demonstration Garden when they share the list of varieties they would like to grow this season.

Seed starting tips

Seed starting kit on left, hydroponic system on right

Sunday, March 8, 2026

I start seeds in a variety of ways.  Indoors I use seed starting trays with peat pellets as well as a hydroponic system.  Outdoors, I’ll start directly in the garden or large pot or I’ll use peat pots or rectangular starting pots then transplant to the garden when they have at least one set of permanent leaves.

For hydroponic systems, you just put the seed in the pd and the system turns the lights on/off at the right time and tell you when they need to be fertilized.  There's more to using the seed starting kits for success.  I’ll focus on starting seeds indoors with the kits you find in the big box or hardware stores in this blog.  It took some time to figure out how to have success with the seed starting kits.  Here is what I have learned.

 I have had the best success using a heat mat and grow light that I leave on during the day and turn both off at night.  Many cool-season loving plant seeds won't even germinate at the higher temperatures the heat mat provides.  By turning off the heat mat at night, it gives the cool season crops the temperatures they need to germinate.  The warm temperatures during the day give the summer lovers the higher temperatures they need to germinate.  The best of both worlds!

Another key learning I had was that you don't want your seed starting medium to be too wet.    You want the medium to be moist.  Sopping wet soil can cause the seed to mold instead of germinate.

This year, I have already started seeds outdoors and in the hydroponic system for the smaller warm season seedlings and harder to germinate types.  At the beginning of April, I will start the larger seeded summer vegetables in small pots or peat pellet tray system.

Seed starting steps

1.      The key is starting with sterile seed starting mix, pots, containers and trays.  For the trays and containers, sterilize with alcohol or bleach solution.  You can make your own seed starting mix with peat moss or coir (renewable), compost, and vermiculite or just buy seed starting mix.  If making your own, be sure to heat the compost to at least 150 degrees to kill any pathogens before using to start seeds.  If you use a system with Styrofoam, putting it out in the summer sun will take care of the hard to remove mold.

2.      Place the seeds in the starter mix in the pots after wetting the soil, peat or coir thoroughly from the bottom (watering from the top can dislodge seeds).  You can also pre-wet the soil before putting into pots.  Make sure to eliminate any air pockets in the soil before planting.  You can lightly press down on the soil with your finger or water overhead before planting the seed.  You don't want your soil mix to be completely wet, but nice and damp.  Seeds need oxygen to germinate.  Waterlogged soil can result in rotted seeds instead of seedlings.

3.      After fully moist, you are ready to put them in a catch pan.  Make sure any catch pan that you use has also been thoroughly sprayed with alcohol or washed in a bleach solution so all pathogens are killed.  Rinse well after sterilizing and before using for seedlings.  I use restaurant style baking sheets.  They hold many seedlings and are super sturdy.

 4.      Make sure you label your seedlings as soon as you plant them; you may think you will remember 2 months from now what was where, but likely not!  Now is also a great time to start keeping a gardening journal.  Start tracking what you planted when so you can review next year what worked well to repeat and what didn’t work so well to tweak.

 5.      I put my seed starts in a tray in a sunny window or under LED grow lights.  Using two T8 fluorescent bulbs or grow light bulbs for 16 hours per day should provide enough light to grow sturdy seedlings.  

6.       Keep moist, but not wet, until seedling emerges.  Water from the bottom so as not to disturb the seed/seedling.  Pour off any standing water to discourage fungal disease.  You can use a spray bottle to keep the seedling and soil damp as well to avoid overwatering or dislodging the seeds.  

7.      Use bottom heat during the day to encourage speedy germination (turn off at night).  As soon as the seedlings have sprouted, discontinue the heat.  Additional heat helps speed germination and reduce the chance of mold or fungal disease.  By only using heat during the day and discontinuing heat after emerging, that has eliminated the dampening off of my seedlings.

8.     Your seedlings will need diluted liquid fertilizer starting 3 weeks after sprouting.  Using a weak fish emulsion is said to help prevent dampening off.  It should be no greater than half strength as these are tiny plants that don't need as much food as a full-size plant.

9.      Don't be too worried if you have leggy seedlings.  Always handle the seedling by its leaves and not its stem.  This reduces the risk that you will bend over, break or crush the stem which kills the seedling.  Once hardened off outdoors, they will strengthen up very quickly.  Once your seedlings have sprouted, gently run your hand over them once a day.  This encourages the stem to strengthen.  You can also use a small fan to blow gently on your seedlings to strengthen their stems to make transplanting safer.

10.    Once the seedling is up and going, spacing them a couple of inches apart helps the plants to grow sturdy stems instead of spindly.  When crowded, the seedlings race to get to the light.  If they are still leggy, it is likely insufficient light.  Make sure you are keeping your artificial light as close to the seedlings as possible (about 2" from the seedlings).  

11.    The best time to transplant is when recommended on the seed packet and when the seedling has nice roots that you can see throughout the soil.  Always harden off before planting.  Make sure the soil is moist and the seedling is fertilized when you plant so it has everything it needs to get growing.

For larger seeds, and seedlings, I start in a 3-4” pot, directly in their garden bed spot or container at the recommended time on the seed packet.  I always start peas and green beans directly in their garden bed spot or pot.  You can grow bush type cucumbers, squash, watermelon and dwarf tomatoes in large pots, too.  Larger seedlings like cucumbers, beans, watermelon, cantaloupe, squash and tomatoes started in a tray, 3-4” pot or peat pellet will need to be transplanted into the garden bed or a larger pot as soon as they have their first set of true leaves.

Seedlings in salad container

 Your seedling’s first leaves are not “true” leaves, think of them as baby teeth.  The second set of leaves are their true leaves.  They are ready to be hardened off when they have their first set of true leaves.  Seedlings must be hardened and not just thrown outside.  You take them out a little at a time, gradually increasing their exposure to sun and cold, only during the daytime.  A week or two should be enough to harden them for the great outdoors.  I try and plant when there is a warm spell and clouds forecasted to minimize the temperature shock and sun scald.

Be sure to keep them watered after transplanting for a couple of weeks to allow their roots to get a good foothold.

It seems I grow more and more varieties from seeds, from flowers to herbs to fruits and veggies.  There are just so many fun varieties out there that you can only get as a seed!  I also have saved seeds from store bought veggies that I thought were cool and tasted great. 

There are great selections of herbs and veggies at nurseries and big box stores nowadays that give you many options, including heirlooms and organically grown.   

You can wait until spring is officially here and pick up plants that looks good in the next month if your first seed starting experiment doesn’t go as well as hoped.  Local gardening centers carry what varieties are best suited for your area.  This is also a great back up if your first seed starting adventure goes a little awry........

What I started indoors this week

Hydroponic seed starting system
Saturday, March 7, 2026 

Now is the time to get the jump on summer harvests and start the warm weather loving seeds indoors.  Here is what I started indoors this week.

Tomatoes-large paste (Italian Red Pear), slicers (5’ Cherokee Purple, OTV Brandywine, Pink Brandywine, red and purple Brandywine), a small fruit (Chocolate Pear), California Tulip, Long Keeper storage tomato, and Tropic VFN and Mannon Majesty from Southern Exposure Seed Exchange that are disease and heat resistant.  

Eggplant-AO Daimura, Antigua, Shiromaru, Amadeo, Qi Ye Round, Italian pink bicolor

Potatoes-Yukon Gold in the potato boxes

Snow peas outdoors in pots with peppers and eggplants

Dragon Tail radish

Cabbage-Hilton Chinese cabbage and 2 Savoy Perfection

Spring Greens-Lettuce (Royal Oakleaf, Butter King, Bronze Beauty, Red Romaine, Yedikule, Red Sails, Chinese Narrow Leaf, New Red Fire, Rouge d'Hiver, Lunix, Solar Flare), Spinach (Spiros F1, Galilee)

Summer Greens-Orach, Amaranth, Japanese Mountain Spinach, Chijimisai, Barese Swiss Chard, Bokoboko Spinach waterleaf, Jewels of Opar, Feaster Family Mustard

Herbs-Rosemary, Pink Celery, Marjoram, Borage, Oregano, Sweet Basil, Papalo

Sweet peppers-Doe Hill Golden Bell storage, burgundy from saved seed, Nadapeno, and a meaty red pepper from saved seed

Strawberries-Alpine varieties Mignonette and Regina

Fruit-Schwartzenbeeren Blackberries (huckleberry), Chichquelite Huckleberry, New Hanover and Mary's Niagara Ground Cherries.

 

I'll start the larger seeds outdoors in another month like cucumber, squash, okra, pole beans, melons and flowers.

What to start 4 weeks before frost (this week)

Starting seeds in peat pods and Aerogarden

Sunday, March 1, 2026

For indoor seed starting, it is time to start the ones that love the hot weather.  You can also continue to succession sow lettuce for continuous harvest into summer.  For outdoors, you can still plant the cool season lovers.  

For our zone 7 garden, here are the ones you can sow indoors now: 

Herbs 

*Basil

*Cilantro

*Culantro

*Dill

*Feverfew

*Navajo Tea

*Butterfly Form Papalo (tastes like cilantro but loves hot weather)

*Red Shiso

Veggies/Fruits

*Amaranth

*Artichoke

*Arugula

*Basil

*Bok Choy

*Broccoli Raab

*Chinese Cabbage

*Cucumber

*Cultivated Dandelions

*Fennel

*Huckleberry

*Lambsquarter

*Leeks

*Lettuce

*Melons

*Mustard

*Okra

*Orach

*Peppers

*Pumpkins

*Radicchio

*Red Malabar Spinach

*Sorrel

*Soybean

*Summer and Winter Squash

*Tomatoes

*Watermelons

Flowers and Ornamentals

*Amaranthus

*Aster

*Blue Fescue

*Cosmos

*Fountain Grass

*Hummingbird Vine

*Hyacinth Bean

*Love in a Mist

*Luffa

*Lupine

*Marigold

*Morning Glory

*Nasturtium

*Platinum Blue

*California and Corn Poppies

*Zinnias

Few of the veggies and herbs listed are cool season producers.  For more on cool season gardening, see A spring edible garden. At this point, we are adding more of the staples of the summer garden like tomatoes, basil, melons and squash.  For more on summer gardening, see  All about the summer edible garden 

For indoor seed starting how-to and tips:  Indoor seed starting how to and tips

For making your own seed starting pots:  Make your own peat pots 

If you are transplanting seedlings from indoors to outdoors, be sure to harden them to the conditions they will be transplanted to.  If in a greenhouse, cold frame or hot bed, you can take outdoors when temperatures are warm or maybe an unheated garage if the temps are close to the covered location you will be placing them.  "Hardening off" seedlings 

Here are the crops you can sow outdoors this week.

Seeds to sow outdoors

Here is a list of the cool season crops you can sow seeds this week in the outdoor garden 4 weeks or less from the last forecasted frost.

Arugula

Beets

Bok choy

Broccoli

Cabbage

Carrots

Cauliflower

Celery

Chard

Chervil

Chives

Collards

Corn Salad

Cultivated dandelions

Endive

Fava beans

Garlic

Kale

Kohlrabi

Leeks

Lettuce

Mache

Mustard greens

Onions

Pac choi

Parsley

Parsnips

Peas

Potatoes

Radicchio

Radishes

Rhubarb

Shallots

Sorrel

Spinach

Turnips

Snow pea seedlings started outdoors in February

March 2026 Garden Planner

March garden with lettuce and spinach

Saturday, February 28, 2026

Spring is about 4 weeks behind last year from previous years.  We've just started having normal temperatures.  Daffodils and crocus only have buds on them.  Daylilies and iris flowers greenery is barely breaking ground.  

If you have not already, it is time to test your soil, get your garden beds ready for planting, finalize the plan for your spring garden and get planting! 

Soil Testing and Bed Preparation

Now is the time to clean up your beds and determine what your soil needs to feed and support your plants through the coming growing seasons.  Remove all the dead plant material still left from last season.  If you had any disease problem, do not compost.  I always leave anything with seed heads through the winter for the birds to eat then remove what remains this time of year.  This year, I am going to scatter flower seed heads on the unmovable bank to see if I can get self-seeders going there.  

You can take a soil sample to your local county co-op extension office to have it tested or buy a do it yourself kit at any big box store or local nursery.  You can do a more extensive soil test by sending your soil sample off to a lab.  Here is a link to my blog on soil nutrition:  The next step in garden production and your nutrit...  Well-fed plants grow better and are more nutritious for you, too.  A win-win.

If you don’t want to go to the trouble of testing, a sure way to enrich your soil is to use a balanced organic fertilizer and compost.  I add organic material every spring with fertilizer and any amendments needed, a layer of compost, then top with hardwood mulch in the garden beds, building the soil’s fertility and its ability to hold water.  This is also when I use amendments to adjust pH if needed.  The soil test I did in the fall of 2023 showed my soil had a pH of 7.8 which is more alkaline than herbs and vegetables do well at so I added sulfur 2 springs ago to bring it down.  I did another soil test last year and it had come down slightly.  Optimal range is 6.5-7.0, so slightly acidic.

A local CSA farmer and organic gardener told me years ago that it is important to not let your fertilizer just lay on top of the ground as many of the nutrients will be lost, especially nitrogen.  My spring routine to build the soil is always to put down an organic fertilizer like Espoma or ReVita Pro, then a layer of compost and top with mulch.  Nitrogen oxidizes easily with the air so be sure to cover your fertilizer with soil, compost or mulch every time you fertilize.  You can make your own balanced fertilizer, too, which is pretty inexpensive.  Make your own all natural, complete fertilizer

If this is your first time gardening, it is super easy to buy plants and put in pots or plant in your established flower beds with your flowers.  I do 100% of my edible gardening in pots and my flower beds.    Easy kitchen garden  How to know what to grow  Surprising veggies that can be grown in pots  If you are really nervous, the easiest garden to start with are herbs.  They love to be neglected!  Just plant them and watch them grow.  My first edible garden was herbs.  Most herbs are perennials so you plant them once and they come back every year.  Start a kitchen herb garden!

Finalize your garden plan

Before your start planting, take pen to paper and finalize your spring garden plan.  Every fall, I capture what went well for the growing season, what I want to learn more about over the winter, and a plan for the coming season.  You will forget if you don't write it down!  A garden journal is a great tool for gardening.

Keep a garden diary 

Reflections on the 2025 garden and the 2026 garden plan

How to develop an edible garden plan

My 2026 Decorative and Edible Garden Plan

The big box stores have out their seed and plant racks so they should have transplants soon.  In our area, they seem to arrive in mid-March.  Seeds are already stocked every place I've been.  Transplants are a good and easy way to look for what will grow well in your area.  The types that like cold weather that will be out soon are cabbage, broccoli, spinach, lettuce, leeks, onion sets, potato sets, blueberry, raspberry, and blackberry bare root plants, along with potted fruit trees.  Spring edible garden

Mid March garden

I have already started lettuce seeds in the portable greenhouses in bare spots.  I have quite a few greens that overwintered under cover.  I'll buy a few lettuce and spinach plants to plant with them.  Keeping them covered during cold spells will keep them warmer and encourage growth so we get fresh salads as soon as possible.  They will do just fine in the garden bed too.  I just love spring salads!

Some varieties I enjoy growing in the spring garden:  

Oakleaf Lettuce-ready to harvest in 45 days  Everything you need to know about growing lettuce

Wild Garden Kales-ready to harvest in 30 days Grow one of the super greens this year-kale

Mesclun Valentine Lettuce mix (red tinted lettuce and greens)-ready to harvest in 30-55 days

Marvel of Four Seasons Butterhead Lettuce (I love the sweet taste of butterheads)-ready to harvest in 55 days Everything you need to know about growing lettuce
Red Sails Lettuce (a ruffled red and green, stays sweet even after bolting)-ready to harvest in 45 days

Space Hybrid Spinach-ready to harvest in 38 days  Grow spinach-a super nutritious, easy green

Gourmet Blend Lettuce (Prizeleaf, Royal Oak Leaf, Salad Bowl, Ashley)-ready to harvest in 45 days

Sugar snap peas-ready to harvest in 70 days Time to plant peas!

All kinds of broccoli or cauliflower-ready to harvest in 50-80 days (leaves are great in salads) Broccoli and cauliflower growing tips

Cabbage-ready to harvest in 68 days.  Cabbage is nutritious and easy to grow

Carrots-ready to harvest in 50-75 days  Grow crunchy, colorful carrots practically year round

Parsley-70 days to harvest  

Potatoes-ready to begin harvest in 70 days  Time to plant potatoes, even if you only have a patio

The above can be companion planted with radishes, beets, chives, garlic, and onions.  Since they are shallow rooted, they grow well with root crops.  Get the most from your space-plant intensively!

When I plant, I plant with a handful of worm compost and char and water in with fish emulsion.  If planting seeds, germination should take anywhere from 4-15 days, depending on how warm the soil is.  I am out in the garden looking for little green shoots daily!  Decorative container gardening for edibles

Important tip-if planting seeds in a mulched bed, be sure to cover the seed with only soil; most seedlings are too weak to push through mulch.  Mulching your beds keeps the weeds from sprouting, too.  Weed free, self fertilizing, till free garden beds 

Potato box

Zone 6/7 Spring Garden Roadmap

Planting seedlings outdoors:

Now (or as soon as the soil can be worked)-fruit trees and vines, nut trees, asparagus, garlic, leeks, onions, peas

Mid-March-cabbage, kale, lettuce, mustards, spinach

Beginning of April-broccoli, cauliflower, cilantro, more lettuce, lemon balm, parsley

Mid-April-corn, marigolds, rosemary, sage, thyme

First of May-basil, chives, cucumbers, peppers, tomatoes

Mid-May-cantaloupe, eggplant, okra, squash, watermelon

Starting your seeds outdoors**:

Now (or as soon as the soil can be worked): peas, spinach, lettuce, radish, mustards

Mid-March: all the above plus arugula, bok choy, cabbage, carrot, collards, leeks, mache, onion. rhubarb, cultivated dandelions

End March:  all the above plus fava beans, beets, broccoli, carrot, Chinese cabbage, cress, kale, kohlrabi, leek, mizuna, parsley, parsnip, early potatoes, turnip

**One watch out is planting seeds too soon.  Seeds have to have a certain soil temperature to sprout.  Plant too soon and the seed will rot and not sprout.  Here are some soil temp guidelines.  Temps to plant seeds outdoors  Be sure to harden off your seedlings before planting outdoors if started inside  "Hardening off" seedlings

Starting your seeds indoors for summer planting:

Now-lemon balm, parsley, sage, thyme, lettuce, cress, chard, basil, broccoli, cabbage, cauliflower, okra, marigolds, eggplant

End of March-cantaloupe, cucumber, lettuce, peppers, tomatoes

A summer edible garden

January is indoor seed starting time! Here is a seed starting calendar........

Indoor seed starting tips

These dates are just guidelines.  You can start your seedlings later and plant your transplants later as well.  Be sure to read the seed packet for what you are starting.  They make all kinds of varieties that are cold hardy and can be planted sooner than what I outlined above.  If you get a cold snap, there are things you can do to protect your early crops.  Extend the season with protection for plants

Happy gardening!