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  • HandoutHandout 1: Supply & Shopping List

    Handout 1: Supply & Shopping List ## Intermediate Vegetable Gardening: Season Extension

    Honestly, you don't need much to add a month or two on either end of your growing season. What you need is the right handful of things and a plan for venting on warm days (more on that in class — it kills more crops than the cold does). Below is what I'd actually buy, split into what matters and what's nice to have.

    Run the numbers on your own bed sizes before you buy anything. A cold frame lid that's the wrong size is just a piece of junk taking up shed space.

    ---

    Budget tier (get these)

    • Old window or storm door, for a cold frame lid — check classifieds first. This is exactly how I built my first one. Free is ideal, five or ten bucks is fine.
    • Scrap lumber, for the frame box — doesn't need to be pretty. Doesn't even need to match. Mine doesn't.
    • A prop stick or a hinge with a stop — non-negotiable. My son's fingers got caught under a lid with no prop the first year we built one. Nobody got hurt bad, but I don't build a lid without a prop arm anymore, no exceptions. Even a piece of scrap 2x2 wedged in works.
    • Row cover fabric (floating row cover, sometimes called frost cloth) — you can find this at most garden centers in the valley by late summer. Buy more than you think you need. It tears, it blows off, you'll patch beds mid-season.
    • U-shaped garden staples or landscape pins — to hold the row cover down. Skip these and the first canyon wind takes your cover to the neighbor's yard.
    • A basic soil thermometer — a few dollars at any hardware or garden store. I check mine more than I probably need to, but for season extension you're planting by soil temp, not by the calendar. The calendar lies to you around here.
    • Good bagged compost or garden soil, not the cheapest bag on the shelf — this is the one place I won't cut corners. Put junk dirt in a nice cold frame and you'll get junk yields. Costco or Macey's runs both work fine for this, whatever's closer.

    Nice-to-have tier

    • A second, dedicated soil thermometer for each bed — I run one per bed because I don't trust a single reading. That's probably more than you need. I said probably.
    • A cheap min/max thermometer for inside the cold frame — tells you the overnight low and how hot it got at midday. Useful for figuring out your venting schedule instead of guessing.
    • Hinges and a proper handle, versus just propping the lid off the frame — makes daily venting faster if you're out there every morning before work.
    • A second row cover in a heavier weight — lighter cloth for the early fall, heavier for real hard-frost nights. I didn't bother with two weights for years. It's a convenience, not a requirement.
    • Drip line, if you're extending into a bed that isn't already on one — worth mentioning here because of our water. Hard water clogs emitters over a summer or two and you won't notice until half your bed dies for no obvious reason. If you're buying new, a filter or occasional vinegar soak on the line will save you a very confusing afternoon later.

    ---

    A shopping note

    Garden centers around the valley clear out row cover and cold frame odds and ends by late fall once everyone assumes the season's over — that's actually a decent time to stock up for next year if you see it discounted. Classifieds are worth checking for windows and storm doors before you buy new lumber and glass. I've never paid for a cold frame lid and don't plan to start.

    Don't over-buy structure. Buy the soil.

  • HandoutSeason Extension Cheat Sheet

    Season Extension Cheat Sheet

    Print this, tape it inside your shed door next to your frost calendar, and glance at it before you make any decisions in October or March. Honestly, most season extension mistakes come from guessing instead of checking. Don't guess.

    ---

    Frost Dates (Utah County, general reference)

    • Last spring frost: typically early-to-mid May at our elevation
    • First fall frost: typically late September to early October
    • These are averages, not promises. The valley will burn you if you trust a warm afternoon. Keep cover ready two to three weeks past your "safe" date on both ends.

    Cold Frame Basics

    • Orientation: slope the lid south, low side facing that direction, to catch the most sun
    • Venting temps: prop the lid open once inside temps hit 75°F. On a sunny 45°F day the box can still cook — vent based on the thermometer inside, not the air temp outside
    • Closing back up: close before sunset once outside temps drop below 40°F
    • Prop arm: build one in, every lid, no exceptions. A dropped lid on fingers is how I learned this one.
    • Material: an old window and scrap lumber work fine. Don't spend real money on the box. Spend it on soil.

    Soil Temperature (Not Air Temperature)

    • Check soil temp 2–3 inches down before you trust "it feels warm enough"
    • Cool-season direct sow (lettuce, spinach, peas): soil at 40°F or above
    • Warm-season transplants (tomatoes, peppers): soil at 60°F or above, consistently, not just one warm afternoon
    • I'll admit I check mine more often than I probably need to. I'd rather over-check than lose a flat of starts.

    Row Covers

    • Lightweight (0.5 oz) for insect protection and mild frost, adds maybe 2°F
    • Medium (1.0–1.5 oz) for real frost protection, adds 4–8°F depending on wind
    • Anchor the edges. Wind here up the canyon will find any gap you leave.
    • Pull covers during the day if temps climb past 60°F under there, or you'll bolt your lettuce early

    Raised Bed Depth (Run the Math First)

    • 8 inches minimum for lettuce, spinach, most greens
    • 12 inches for root crops and anything you want to overwinter
    • Before you build deep: a 4x8 bed at 12 inches is about 32 cubic feet of soil. That's roughly eleven wheelbarrow loads. Know that before you dig, not after.

    Irrigation Note (Our Water, Specifically)

    • Hard water clogs drip emitters over a season, especially the far end of a line
    • If plants at the end of a bed are struggling and everything else looks fine, check the emitters before you blame the plant
    • A vinegar soak clears most mineral buildup. Takes patience, not much else.

    Jordan's Short List of Opinions

    • Cold frames beat hoop houses for most home gardens. Cheaper, easier to vent, you'll actually use it.
    • Buy good soil. Build the structure out of whatever you've got lying around.
    • Grow what your family actually eats. Don't extend the season on something nobody's touching.

    That's the whole sheet. If something on here doesn't match what's happening in your own yard, trust your own thermometer over my numbers. Every yard in this valley sits a little different.

  • WorksheetSeason Extension Planning Worksheet

    Season Extension Planning Worksheet

    Fill this out as we go through class, not after. Half of this is stuff you need to actually walk out to your garden and check, so bring a pencil that works outside.

    ---

    Part 1: Your Frost Reality

    Forget the almanac date for a second. This is about your yard.

    • Average last spring frost date (official): _______________
    • Last three years, when did you actually get a late frost that surprised you? (Ask around, check your own notes if you kept any.) _______________
    • Coldest, lowest spot in your yard (cold air pools — walk it and look for frost patterns some morning): _______________
    • Do you have a frost calendar somewhere you'll actually see it? Where will you put it? _______________

    Honestly, the calendar taped inside the shed door is what works for me. Doesn't matter where yours goes, as long as you'll see it in April when it's 68 degrees and everything in you wants to plant tomatoes.

    ---

    Part 2: What's Actually Worth Extending

    Run the numbers on this before you build anything.

    List what your household actually eats, in order:

    1. _______________
    2. _______________
    3. _______________
    4. _______________

    Circle the ones from that list that are cold-tolerant (lettuce, spinach, carrots, kale, beets, chard). Those are your season-extension candidates. If your family's favorite thing is corn or squash, I'll be honest, there's no cold frame that's going to help you there. Grow those in season and let it go.

    ---

    Part 3: Structure Choice

    Cold frame or hoop house? Circle one, and write why.

    Cold frame ☐ Hoop house ☐

    Reason: _______________________________________________

    My opinion, for what it's worth: cold frame, for most yards this size. Cheaper, easier to vent, and you'll actually open and close it instead of avoiding a big tunnel because it's a production.

    Materials on hand or free:

    • Old window or storm door? ☐ Yes ☐ No — source: _______________
    • Scrap lumber? ☐ Yes ☐ No
    • Hinges, a prop stick or arm (non-negotiable, more on that below): ☐ Have it ☐ Need it

    Size math — do this before you build, not after:

    Bed length ___ × width ___ × planned soil depth ___ = ___ cubic feet of soil needed

    (I built one a foot too deep once without doing this math first. Eleven wheelbarrow loads and a second trip for bags. Don't be me.)

    ---

    Part 4: Venting Plan

    This is the part people skip and regret.

    • What's your plan for venting on a sunny 45-degree day? _______________
    • Do you have a way to check it midday, or does it need to be automatic (vent arm, thermostat opener)? _______________
    • Thermometer placed inside the frame? ☐ Yes ☐ Need one

    More cold frame crops die from cooking than from freezing. It feels backwards until you lose a tray of lettuce to a sunny afternoon you didn't think twice about. So check it.

    ---

    Part 5: The Two Things Nobody Warns You About

    • Hard water: if you're on drip irrigation, when did you last check your emitters for buildup? _______________ (Vinegar soak works. Ask me about my one bad summer if you want the whole story.)
    • Dry air: how are you watering the frame — do you have a plan for it drying out faster than the rest of the bed? _______________

    ---

    One Line to Finish Before You Leave Today

    "The one thing I'm building or fixing before the first cold snap is: _______________________________________________"

    That's it. Bring this back next week and we'll compare notes on what changed once you actually measured your own yard instead of guessing.

  • HandoutHandout 4: Season Extension Troubleshooting

    Handout 4: Season Extension Troubleshooting

    Most of these problems show up in the first year or two of running cold frames or covers. Here's what actually happens, and what I'd do about it.

    1. Everything under the cold frame is wilted and cooked by afternoon

    You didn't vent it. This is the number one killer, more than cold ever is. A sunny 45-degree day can hit 90-plus inside a closed frame by noon. Prop the lid a few inches once the sun's been on it an hour or two, and check it again mid-afternoon. Yes, every day it's sunny. I know.

    2. Row cover is sagging onto the plants and crushing them

    You need hoops. Cover laid straight on foliage will mat it down, especially after snow or a hard frost adds weight. Wire or PVC hoops every few feet solve this. Cheap fix, easy to skip, don't skip it.

    3. Plants under cover look fine, then die overnight

    Check whether the cover actually touched the ground on all sides. Gaps let cold air pool right where your plants are. Cover needs to be sealed to the soil with rocks, boards, soil itself, whatever you've got, or it's not doing its job.

    4. Frame or bed is bone dry even though you're watering

    Row covers and cold frame glazing block a lot of rain and cut down on airflow, so soil dries differently than you expect. It's not always more water you need, sometimes it's checking more often, because the schedule that worked outdoors won't hold once there's a cover on.

    5. Water barely comes out the far end of the drip line

    Hard water. Ours out here is bad, and it clogs emitters slowly enough that you don't notice until half a bed is struggling. Pull the emitters and soak them in vinegar for a few hours. I lost most of a summer figuring this out before I knew that's what it was. Now I do it as maintenance, not as a fix.

    6. Seeds aren't germinating in the cold frame even though it "feels warm enough"

    Soil temp and air temp are not the same thing. Get an actual soil thermometer and push it a couple inches down. Most cool-season crops want soil in the 40s at minimum to bother germinating. I check mine more than I probably need to, honestly, but I'd rather know than guess.

    7. Lid is heavy and slams shut on its own

    Build in a prop arm. Not optional. My son caught his fingers under a cold frame lid years ago because we hadn't thought about it, and nobody got hurt bad, but that's pure luck, not good design. Every frame I've built since has a stick or a hinged arm holding it open.

    8. Frame filled with condensation, everything's damp and moldy-smelling

    Same root cause as the cooking problem: not enough venting. Damp, still air under glazing breeds mold fast, especially on lettuce and spinach. Crack it open earlier in the day, even on cloudy days, so moisture has somewhere to go.

    9. You covered plants for a frost that never got that cold, and now you're not sure if it was worth it

    Honestly, you cover anyway. Frost dates are a suggestion, not a promise, and the valley will burn you the one time you decide to skip it. I'd rather vent an unnecessary cover than lose a bed of spinach in late April because I trusted a calendar.

    10. Frame or bed is too big to manage and you're dreading dealing with it

    Run the numbers before you build, on size and on how much venting and watching you're actually willing to do. I built a bed a foot too deep my first year because I over-read on soil depth without doing the volume math, and it cost me eleven wheelbarrow loads and a second trip for soil. Smaller and simple wins here. A cold frame you'll actually open every day beats a hoop house you dread dealing with.

  • podcast_scriptClass podcast — episode 1

    Audio coming soon — show notes below.

    JESS: —okay but eleven wheelbarrow loads. That's the part I can't get over.

    JORDAN: It's a lot of dirt. Honestly, I didn't run the numbers first, and that's kind of the whole lesson right there.

    JESS: For anyone just tuning in, we are mid-conversation already, which is how these always start with Jordan. This is the podcast for Intermediate Vegetable Gardening: Season Extension, I'm Jess, I produce these things for Utah Community Learning, and Jordan Andersen is teaching the class. Jordan, back up ten seconds. What wheelbarrow story.

    JORDAN: First raised bed I ever built for extending the season, I over-read on soil depth. Some article said deeper is better for root crops and heat retention, so I built it a foot deeper than I needed to. Didn't stop to think about what that means in actual volume of dirt.

    JESS: And what does it mean.

    JORDAN: Eleven wheelbarrow loads. I had to make a second Macey's run for bags because I underbought that bad. My back knew about it for a week.

    JESS: Did you tear the bed out?

    JORDAN: No, I kept it. It works fine, it's just overbuilt. I tell people now, run the numbers on the volume before you build anything. Length times width times depth, figure your cubic feet, then go buy soil. Takes five minutes and saves you a Saturday.

    JESS: That's a genuinely useful tip for somebody who isn't even taking the class, by the way. Do the math before you dig.

    JORDAN: That's basically it. Cheap lesson to learn on paper, expensive one to learn with a shovel.

    JESS: So season extension. For people who don't know what that even means yet, give me the one-sentence version.

    JORDAN: Getting more growing days out of the year than the calendar wants to give you. Up here we've got a short window between the last hard frost in spring and the first one in fall, and most people just accept that window as fixed. It's not, really. You can push both ends of it if you're willing to build a couple simple things and pay attention.

    JESS: And this is not your first rodeo with pushing the calendar.

    JORDAN: Oh man, no. My first year gardening at all, I planted tomatoes the second week of May because it was warm. Just, warm afternoon, felt like spring was here, so I put them in. Frost came back the third week of May and wiped out every single plant.

    JESS: Every one.

    JORDAN: Every one. I replanted, and I've had a frost calendar taped inside my shed door ever since. That's opinion number one of this whole class, honestly: frost dates are a suggestion, not a promise. The valley will burn you if you trust a calendar over the actual weather.

    JESS: Okay, here's the anecdote I wanted you to tell, because I think it fits with this session. Tell the carrot one.

    JORDAN: The Lincoln one?

    JESS: Yeah.

    JORDAN: So this ties into extension a little sideways, because it happened in one of the beds I was experimenting with for fall crops. Lincoln was three at the time, and he wanted to help in the garden, which is great, except three-year-olds don't know the difference between weeding and just pulling things up. He got into a row of carrot seedlings I'd just thinned and pulled up about half of it thinking he was doing a good job.

    JESS: What did you do?

    JORDAN: Replanted what I could save, let the rest go. Wasn't worth making a thing of it. You either garden with little kids around or you don't garden for about a decade, so I've made peace with losing some percentage of every bed to help I didn't ask for.

    JESS: That's a very zen way to talk about your carrots getting murdered by a toddler.

    JORDAN: Well, five years in, you pick your battles. The bed still produced. It just produced a little less carrot and a little more life lesson.

    JESS: Okay, so this first session, what are people actually walking out with.

    JORDAN: We're talking frost dates for real, not the printed ones, the actual behavior of our specific microclimates depending where you are in the valley. And we're starting the case for cold frames over hoop houses, which is a little bit of an opinion of mine.

    JESS: Mildly contrarian, I'm told.

    JORDAN: A little. Everybody wants the big hoop tunnel because it looks impressive. A cold frame is cheaper, it's easier to vent, and you'll actually use it every day instead of it becoming a monument in your yard. Simple wins, most of the time.

    JESS: And next session you're building one.

    JORDAN: Next session we build one, start to finish, and I'll walk through venting, because more stuff dies in a cold frame from cooking on a sunny 45-degree day than from actual cold. Sounds backwards. It's true. You have to crack that lid or you'll bake your spinach by ten in the morning.

    JESS: Bring a window if you've got one lying around, is that right?

    JORDAN: If you've got an old window sitting in a garage somewhere, bring it. That's literally how my first one got built, off a free listing. We'll talk lids and hinges and why you always, always build in a prop arm.

    JESS: There's a story there too but we're out of time for it.

    JORDAN: There's a story there too. We'll get to it.

    JESS: Alright, that's session one. See you all next time, bring your garages' worth of old windows.

  • podcast_scriptClass podcast — episode 2

    Audio coming soon — show notes below.

    JESS: —okay but that's the part I didn't get until you said it just now. People think the cold frame lid is a set-it-and-forget-it thing.

    JORDAN: It's the opposite of that. Honestly, more stuff dies in a cold frame from cooking than from freezing. You get one of those sunny 45-degree days in March, the box turns into an oven, and by afternoon your lettuce looks like it went through a dehydrator.

    JESS: Which seems backwards.

    JORDAN: It is backwards. That's why nobody believes it till it happens to them. I didn't believe it either.

    JESS: So you have to vent it.

    JORDAN: You have to vent it. Prop the lid, even just an inch or two, any time it's sunny and above freezing. That's the tip. If someone's listening to this and never takes the class, that's the one thing I'd want them to walk away with. A cold frame without a vent plan is just a very slow way to kill your plants.

    JESS: Speaking of lids. You have a story about a lid.

    JORDAN: Oh man. Yeah. So this was the first cold frame, the one Bryce and I built out of an old window we got off a classifieds listing, free, which felt like a great deal at the time.

    JESS: Free window, what could go wrong.

    JORDAN: Right, well, the glass in an old window is heavier than you think it's going to be. We got the frame built, propped the lid open so he could reach in and settle the soil, and it just — slipped. Came down fast. Caught his fingers.

    JESS: Oh no.

    JORDAN: He was fine, nothing broken, but he screamed and I about had a heart attack. And that's the last time I ever built a lid without a prop arm. Doesn't matter how small the frame is now. Every single one gets a stick or a hinge arm that holds it open on its own, no exceptions, because I am not doing that again and I'm not doing it to somebody else's kid either.

    JESS: That's a good rule.

    JORDAN: It's a rule because I learned it the bad way. Most of my rules are like that.

    JESS: Okay, switching gears a little — you mentioned run the numbers on soil depth last class and someone asked me afterward what that actually means in practice.

    JORDAN: It means before you build anything, figure out the volume of dirt you're committing to. I built a bed once that was a foot too deep because I'd read that deeper is better for root crops and didn't stop to do the math on what a foot of extra depth costs you in cubic feet of soil. Ended up needing eleven wheelbarrow loads to fill it. Had to make a second run to Macey's for more bags halfway through a Saturday because I completely underestimated it.

    JESS: Did you keep the bed?

    JORDAN: Kept the bed. It's fine, it just grows very deep carrots now whether I need them that deep or not. But yeah — length times width times depth, in feet, before you buy anything. Takes five minutes and it'll save you a wasted trip.

    JESS: That's the kind of thing you don't think to check until you're standing in the aisle.

    JORDAN: Exactly. So.

    JESS: So. Next session we're building the actual cold frames, right, hands-on.

    JORDAN: That's the plan. Bring old windows if you've got them, or we've got scrap lumber and some hardware cloth for anyone starting from nothing. We'll go through venting setups, the prop arm situation we just talked about, and I want to get into what's actually worth growing in one of these out here. Spinach, lettuce, root crops — stuff your family will actually eat, because there's no point extending your season on something nobody's going to touch.

    JESS: No mystery kale nobody wants.

    JORDAN: No mystery kale. So bring your calendar too if you've got frost dates written down anywhere, because we're going to talk about when to actually put things out, not when the calendar says you're supposed to.

    JESS: Perfect. Alright, that's episode two —

    JORDAN: Watch your fingers on lids, everybody.

  • podcast_scriptClass podcast — episode 3

    Audio coming soon — show notes below.

    JESS: —okay but that's the part I don't get. Why does venting matter more than the cold itself?

    JORDAN: Because the cold isn't usually what kills the plant. Honestly, more of my cold frame crops have died from cooking on a sunny 45-degree day than ever died from frost. People hear "cold frame" and think the danger is nighttime. The danger is ten a.m.

    JESS: That seems backwards.

    JORDAN: It is, until it happens to you. You've got a closed box with a clear lid sitting in the sun. Even when it's chilly outside, the inside of that frame can hit eighty, ninety degrees by midmorning. Your lettuce doesn't know it's February. It just knows it's suddenly a greenhouse and it's stressed.

    JESS: So you have to physically open it.

    JORDAN: You have to physically open it. Prop the lid, even just a few inches, once the sun's on it. Close it back up before the temperature drops in the afternoon. That's the whole job. It's not glamorous, but it's the job.

    JESS: This feels like a good spot for the vinegar story. Am I wrong?

    JORDAN: No, you're not wrong, though that one's technically an irrigation problem, not a venting problem. Different lesson, same theme, which is: the valley will find the thing you didn't think about.

    JESS: Tell it anyway.

    JORDAN: So my second season, I've got drip line running through a raised bed, and the far end just keeps dying. Same water schedule, same sun, same everything, and the far end looks fine for a while and then it doesn't. I figured it was soil, so I dug it up. Fine soil. I figured it was sun, moved plants around. Didn't matter.

    JESS: How long did this go on?

    JORDAN: Most of a summer. Oh man, it was embarrassing how long it took me. Turned out the emitters at the far end were clogging up with mineral buildup from our water. It's hard water out here, and it just cakes up inside those little emitters over time, slower flow, less water, dead plants at the end of the line. I finally pulled a few emitters and soaked them in vinegar and watched years of buildup just dissolve.

    JESS: And you tell people this because—

    JORDAN: Because half the valley has this exact problem and doesn't know it. If you've got drip irrigation and one end of a row is always struggling for no reason you can find, check your emitters before you blame anything else. Soak them in plain vinegar, twenty minutes or so, rinse, put them back. Cheap fix. I wish someone had told me in June instead of August.

    JESS: That's the tip. I'm calling it now, that's the takeaway line for people who aren't even in the class.

    JORDAN: That's fine by me. It's a good one to just hand out.

    JESS: Okay, venting and vinegar. What else should people expect walking into a cold frame for the first time?

    JORDAN: That it's less finicky than they think, once they get the venting rhythm down. I know some people prop it in the morning and forget, and some people rig up an automatic vent opener, which honestly I'd probably do too if I were less stubborn about building things myself. Either way works. The failure mode is forgetting it exists.

    JESS: Which happens.

    JORDAN: Which happens to everybody at least once. You lose a tray of starts and you don't forget again.

    JESS: Alright, so next session, we're actually building the frames.

    JORDAN: Right, we're building. Bring the measurements from your bed if you've got them, and if you've got an old window sitting around, bring that too, that's your lid, free lid beats bought lid every time. We'll go over the prop arm setup in detail, because that's not optional in my class.

    JESS: You've mentioned that a couple times now.

    JORDAN: I'll mention it every time. My son Bryce got his fingers under a lid on our first frame because we didn't think about how heavy an old window actually is, and that's the last time I ever built one without a prop arm holding it open. So. No exceptions, every frame we build has one.

    JESS: Noted, loudly. Alright, that's it for this one. Bring your window, bring your measurements, we'll see you at the next session.

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