Updates, Verifications & Instructions

We're growing in three kinds of container this year — the raised bed (the "box"), fabric grow bags, and now the sunflower frame — and the soil isn't the same in each. Here's the recipe for every one.

The box (raised bed)

The raised bed is filled with a blend of Landscapers Pride potting soil and composted cattle manure — roughly two parts soil to one part compost (the ratio Sam worked out). The University of Maryland Extension backs this kind of 1:2 compost-to-soil ratio for raised beds. The basil and parsley are already in it, and the marigolds go straight into the same mix — no change needed.

The pepper's 10-gallon bag — same as the box

The jumbo jalapeño gets the exact same compost-amended mix as the box. Peppers like a near-neutral soil (about pH 6.0–7.5), which that blend already provides. Do not add acidifier to the pepper bag.

The blackberry 25-gallon bags — different: acidified

Blackberries prefer a slightly acidic soil (around pH 5.5–6.5), lower than the box mix. So the blackberry bags get their own recipe:

1. Fill the bag mostly with potting mix.
2. Keep compost light — no more than about a fifth of the mix — or skip it and feed with Berry-Tone later. (Composted manure is near-neutral and works against the acidity you're trying to create.)
3. Mix in the Espoma Soil Acidifier — see the next section for exactly how much.
4. Plant one blackberry per bag — don't crowd two into one.

The product Sam picked up is exactly right: Espoma Organic Soil Acidifier is elemental sulfur plus gypsum, it's listed for organic gardening, and the bag itself notes it's safer than aluminum sulfate. It's the blackberries' job — not the pepper, not the box.

How much per 25-gallon bag:

1. Use the bag's "Potted Plants" rate: 1 tablespoon for every 4 inches of pot diameter.
2. Measure across the top of your 25-gallon grow bag — it's roughly 21–23 inches across.
3. Divide that by 4. That comes out to about 5–6 tablespoons per bag.
4. Mix it evenly through the whole bag of soil before planting — worked all the way through, not just sprinkled on top.

Two things worth knowing: sulfur works slowly — it nudges the pH down over a few weeks as the plant settles in, so there's no rush, and the label notes it won't burn the roots. And blackberries aren't as acid-hungry as blueberries, so one gentle dose now is plenty — you can re-check with a $10 pH kit in 6–8 weeks and add more only if it's still high.

Good news on Sam's new frame: sunflowers are the least fussy plant in the garden. University extension sources describe them growing in "virtually any soil." The one thing they genuinely need is drainage — soil that isn't constantly soggy. They are not acid-lovers, and they don't need a premium mix the way the blackberries do.

For the new sunflower bed:

1. Loosen the native soil inside the frame — turn it over or work it with a hand cultivator so it isn't compacted.
2. Mix in a few inches of compost or composted manure. Sunflowers — especially the big branching and giant types — are fairly heavy feeders, so organic matter plus a slow-release fertilizer keeps them strong.
3. No acidifier and no special potting mix needed — near-neutral soil (about pH 6.0–7.5) is fine.
4. Full sun — the spot needs at least 6 hours of direct sun a day. The garage-side location works.

Two extras for the big varieties: space giant or mammoth sunflowers about 2 feet apart, and be ready to stake them — tall sunflowers get top-heavy and catch the wind. And remember the sunflowers' real job is as a trap crop: they earn their keep by being scouted for leaf-footed bugs, so having the bed a short walk from the tomato box — not right beside it — is exactly right.

The nasturtium seed has been slow to come up. First: that's normal — nasturtium can take a couple of weeks to sprout, so give it until about day 14 before deciding it failed.

If you'd like a backup, the best stand-in is sweet alyssum. It's a low, carpeting plant — much like nasturtium's spot at the edge of the bed — and the University of Illinois Extension notes it draws in hoverflies and ladybugs, beneficial insects whose appetite for aphids makes alyssum a genuinely good border plant for aphid control. Dog-safe — confirmed non-toxic to dogs by the ASPCA, so it's fine with Lulee.

Calendula (pot marigold) is another Dog-safe option if you'd like a second flower — just note the dog-safe one is Calendula, a different plant from the French marigolds already in the bed. And if the nasturtium does come up after all, there's no harm in keeping all of them.

We ended up with four blackberry plants across three varieties. Here's what the research turned up — including one honest finding.

• Prime-Ark Freedom (two plants) — a University of Arkansas variety, and the world's first thornless primocane-fruiting blackberry, meaning it can fruit on first-year canes. You may see berries within months.
• Ouachita (one plant) — a University of Arkansas variety from 2003, well documented by extension services. Erect, self-supporting canes; needs only 300–500 chill hours (a comfortable fit for Central Texas); early-season fruit over about a five-week window; resistant to rosette disease.
• Big Daddy (one plant) — the honest finding: "Big Daddy" is a nursery trade name, and unlike the other two there is no published university research on it. We treat it as a standard thornless blackberry and give it the general care. It arrived from the nursery already carrying berries, so it has a head start. (Worth keeping its nursery tag — it may list a documented cultivar name.)

The detail that matters for care: Ouachita and Big Daddy fruit on second-year wood; Prime-Ark Freedom can fruit on first-year wood. That changes how each is pruned. The full per-variety care and pruning is on the Plant Guide, and the week-by-week timing is on the Care Calendar.

Every answer on this page is grounded in university and cooperative-extension sources — advice that has been trialed and reviewed, not just posted online. The blackberry and pruning guidance comes from Texas A&M AgriLife, the University of Maryland Extension, LSU AgCenter, and Ohio State University. The companion-plant and dog-safety answers come from the University of Illinois Extension and the ASPCA. The sunflower guidance comes from the extension services of Texas A&M, Minnesota, Georgia, Clemson, West Virginia, Missouri, and Illinois. The soil-acidifier amounts come from the product's own label.