How to Use Floral Foam (the Right Way): Tips for Beginners from a Floral Designer

If you’ve ever felt like flower arranging is a battle between beauty and balance, floral foam might just be the unsung hero you’re avoiding. I say it all the time - foam is your friend! And I mean it. Whether you're styling a table for a party or just making Tuesday’s grocery store bouquet look intentional, floral foam makes the whole process easier, cleaner, and actually fun.

In this guide, I’ll walk you through exactly how to use floral foam the right way (no mushy messes), share a few pro tricks, and hopefully convince you that this little green block deserves a permanent spot in your floral toolbox.

What is floral foam (and which type should you use)?

Floral foam has been making flower arrangements easier since the 1950s, when a chemist named Vernon Smithers developed a way to keep cut stems supported and hydrated. (Honestly, legend behavior.) Today, florists still rely on it, most often the green stuff known as Smithers-Oasis Wet Floral Foam, which holds up to 95% of its weight in water.

But here’s the thing: not all floral foam is created equal. There are two main types, and choosing the right one makes all the difference.

You’ll find specialty versions too: foam made for spring flowers, heavy arrangements, or oddly shaped containers. Some newer versions even claim to be biodegradable, which, let’s be real...is a step in the right direction.

For this post, I’m sticking to the standard green floral foam you can pick up at your local craft store. It’s affordable, accessible, and works beautifully once you know how to handle it. And yes, I’ll cover both wet and dry foam, because even if you’re loyal to one type, there’s a good chance you’ll need the other someday. (Looking at you, faux flower people.)

Why use floral foam in your next arrangement

Whether you're working with wet or dry foam, there are a few very good reasons to add it to your floral supplies:

1. It makes arranging easier.
Wet floral foam holds water and your stems so once you place a flower, it stays put. No floppy blooms. No floral tape gymnastics. No chicken wire wrestling. Just saturate the foam, tuck it into your container, and start designing.

2. It’s easy to find.
You can grab floral foam online or at just about any craft store. It’s not some niche florist-only tool - it’s widely available and affordable.

3. Your design will actually stay together.
Foam gives your arrangement structure. That means it's easier to transport, shift around, or place on a table without worrying about flowers sliding out or toppling over.

Let’s break it down, wet and dry floral foams both offer support and structure, but they serve different purposes and behave differently. Each deserves its own spotlight.

Wet floral foam (for fresh flowers)

Wet floral foam is the go-to tool when your arrangement needs both hydration and structure. I use it when I want total control over where each stem lands. It’s especially helpful for big centerpieces, event work, or anything that needs to stay intact while being moved.

How to soak wet floral foam

There are two main methods here. Some florists prefer the float-and-soak approach, where you let the foam sit on top of a bucket of water and slowly sink on its own. This helps prevent air pockets from forming. Watching it soak can actually be kind of relaxing.

At home, I usually set the dry foam directly in my container and pour water over it. It may not be the gold standard, but it gets the job done and the flowers stay hydrated.

Pro Tip: Never dunk the foam under water. It can trap air inside and leave dry spots in the middle.

How to fit wet foam in a vase

Think of this like building a puzzle. You want the foam to fit snugly into your container. If it’s too loose, it won’t hold anything steady. If it’s too tight, it could crack. Use a floral knife to trim it down to size, and keep scraps nearby to wedge into any gaps.

If you're using shallow trays or low dishes, Oasis tape helps secure the foam. Just be sure the surface is clean and dry before you apply it.

How to cover it for a professional look

Green foam doesn’t stand out too much, but it’s still best to hide it. I usually lay down sheet moss before arranging, or I’ll tuck in fresh greenery like pittosporum or ruscus. You can even get creative with bits of curly willow or eucalyptus if the container calls for it.

How to design in wet foam

Cut stems at a sharp angle to help them slide into the foam. Always give each stem a fresh cut before placing it. Wet foam gives you complete flexibility with placement. You can angle stems in any direction without worrying that they’ll shift or flop.

I like to start with line flowers to define the shape. Then I add focal blooms and finish with filler flowers. Once a stem is in, it stays put. That kind of stability is a huge help when you're transporting arrangements or setting up an event.

Pro Tip: If you need to move a stem, don’t push it into the same hole. Shift over a bit and reinsert. This avoids air gaps that could reduce water uptake.

Dry floral foam (for faux or dried flowers)

Dry floral foam is your best friend when you're working with anything that doesn't need water. Think silk flowers, dried stems, faux greenery, or a basket full of seasonal stems. This foam is dense, crumbly, and much lighter than its water-loving cousin. I keep a few bricks in my floral supply tool closet at all times. It’s saved many last-minute projects and forgotten centerpieces.

How to fit dry foam in a vase

Dry foam works a lot like wet foam when it comes to sizing. You want a snug fit, not a wobbly block that shifts every time you touch it. I use a floral knife or even a serrated kitchen knife if that’s what’s clean. Start with one big piece in the center and fill the rest with smaller bits. Dry foam is forgiving. You can shove it around a little without breaking it in half.

For oddly shaped containers like baskets or footed bowls, I sometimes hot glue the foam in place. You only need a few dabs. Just don’t be surprised when it stays stuck forever.

How to cover the foam

Dry foam usually comes in a charming shade of neon green or dead-leaf brown. Either way, cover it. I like to use preserved moss, faux greenery, or whatever bits I have leftover from other projects. If I’m doing a rustic or farmhouse-style arrangement, Spanish moss adds great texture. Bonus: it hides a multitude of sins, like uneven foam or those flower stems that didn’t quite land where you meant them to.

Pro tip: I always keep floral wire nearby. Cut it into short lengths, bend into a “U” shape, and use it to pin moss securely onto the foam. It’s quick, easy, and keeps everything right where it should be.

How to arrange in dry foam

This foam is dense and a little stiff, so you’ll need some pressure to get stems in. Luckily, most faux flowers come with wired stems. Just give them a bend if they resist. And don’t forget to use wire cutters. Regular scissors will hate you for it.

Unlike water arrangements, dry foam gives you total freedom with placement. Want a stem sticking straight out to the side? Go for it. Designing with dry foam feels like building a permanent sculpture. Once it’s in, it stays. You can tilt, layer, or create all sorts of movement without worrying that your masterpiece will collapse on the car ride over.

Floral foam tips from a pro

Whether you’re elbow-deep in a centerpiece or nervously prepping for a school fundraiser centerpiece marathon, these tried-and-true foam tips will help you stay sane and keep your flowers standing tall.

Do’s and don’ts

Do:

• Pre-cut your foam bricks if you're working with multiple arrangements.
• Use sharp floral knives or a serrated blade for cleaner cuts.
• Keep your floral foam stored in a dry, sealed bag until use (yes, even the wet kind).
• Give flowers a fresh angled cut before inserting them.

Don’t:

• Shove stems in and twist them around. You’re just creating air pockets.
• Soak foam by dunking it under water. Float it instead and let it absorb.
• Reuse foam once it's been punctured all over. It loses structure fast.
• Skip covering the foam with moss so if there are any gaps in your design, you’re not staring at a block of green.

Favorite hacks

Pick the right container: Foam plays nice with most vessels — trays, compotes, baskets, even that vintage tin you forgot you had. The trick is a snug fit. If it wiggles, back it up with floral tape or chicken wire.

Don’t overlook foam forms: Foam isn’t just bricks. Wreaths, rings, heart -shaped wreaths, cages, and bouquet holders open up a whole new world of design options. I used a foam wreath form for this fresh flower candle ring, and it worked like a charm.

Stick with one foam: Mixing dry and wet foam in one design sounds clever until it’s not. Keep it simple and commit to the type that fits your flowers. Stability wins.

More designer tricks

If you’re ready for the next level, check out my Floral Design Index where I keep all my best tutorials and floral hacks in one place.

You can also browse my top must-have flower arranging supplies for the tools I actually use at home, or try your hand at a design lilies like a pro post to see foam in action with everyday blooms.

Frequently asked questions