For the themes of fruit and flowers, there are many excellent options in all prices ranges to fit your family budget.
The classic dozen of red roses is of course a suitable option, or perhaps a flower of the month club. A yummy fruit basket filled with seductive fruits like strawberries and peaches, or exotic fruits like kiwi, figs, mango, or an Asian fruit would also be a great choice. Flowering fruit trees cover both traditional gifts of flower and fruit.
In terms of jewelry, you have several options. You can go for a jewelry design that evokes the essence of flowers through design or preserved petals. Or try blue topaz and blue zircon as the alternate modern materials for the fourth anniversary. Blue topaz is a particularly pretty stone yet also quite affordable for a young family on a tight budget, so that would be our recommendation if you didn't find a floral design you like. (see links below)
Using another one of the modern 4th anniversary materials, a silk scarf - particularly one with a flower pattern or subtle hint of one - would also be a great gift idea. A gift for the couple could be some silk flowers for the home.
If your husband is not into fruit, then your best option is to skip right to the modern materials of linen or nylon. Think about whether your husband's sports or hobbies might have memorabilia or gear that use these materials. One example would be a nylon sports jersey of his favorite professional team. Other ideas are team hats, t-shirts, beach towels, and winter scarves.
Additional traditional or modern anniversary materials also provide a wide range of possibilities for decorating your new home together with high thread count linens, curtains, and plush towels. Alternatively, a home appliance for the kitchen or home entertainment system would make great purchases.
My wife and I have always been interested in gardening, but in recent years we have both been too busy with work to invest much time in our new yard. So this year we decided to renovate our garden together for our fourth anniversary. It was great because we took special time out of our busy schedules to plan and implement the project together. -- David and Sue
We are pregnant with our first child! Picking up the fruit idea of this year's anniversary, we bought a plum tree from our local nursery, and my husband planted it in the back yard. It is about five feet tall right now. The idea of this is that each year as our child grows, we will see the plum tree grow and someday it will produce fruit that our kids can pick. -- Anna
Okay, this is not for prudes but on our fourth anniversary I bought some sensuous fruits like strawberries, cherries, peaches, bananas, and cream and then arranged a platter suggestively before my husband got home so that he would see it first thing when he walked in from work (I was in the other room waiting for him with a cute cherry lingerie number on and the can of whipped cream). I heard his gorgeous laugh a few moments after he put down his keys. He told me later that it made his day! -- Anonymous